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* 















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— 


ENGINEER DEPARTMENT, U. S. A. 


n f] 

\J5Mod 


o If, b, GXnvv, 


R E P 01! T S 


<A. 




UPON 


S5i 


FORT SAINT PHILIP CANAL 


AND 



- „ 




CONSTRUCTION OF JETTEES 


FOR 


THE IMPROVEMENT OF THE MOUTHS OF THE MISSISSIPPI. 


■ C 

» • O 


* > ' 


WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1874 . 























nCP 7 \909 

%®r l* 







43d Congress, » HOUSE OF REPRESENTATIVES. ( Ex. Doc. 
ls« Session. ( \ No. 220. 


CANAL CONNECTING THE MISSISSIPPI RIVER WITH THE 

GULF OF MEXICO. 


LETTER 

FROM 

THE SECRETARY OF VAR, 

IN RELATION TO 

The ship-canal to connect the Mississippi River with the Gulf of Mexico. 


April 17, 1874.—Referred to the Committee oh Railways and Canals and ordered to be 

printed. 


War Department, April 15, 1874. 

The Secretary of War has the honor to transmit to the House of 
Representatives, in connection with his letter of the 4th of February last, 
relative to the ship-canal to connect the Mississippi River with the Gulf 
of Mexico, (published in House Executive Document 113, copy here¬ 
with,) Report of the Chief of Engineers, dated the 15th instant, and 
accompanying papers upon the same subject. 

* WM. W. BELKNAP, 

Secretary of War. 


Office of the Chief of Engineers, 

Washington , D. C., April 15, 1874. 

Sir : In transmitting the reports of the board of engineers upon the 
ship-canal from the Mississippi River, near Fort St Philip, to Isle au 
Breton Pass, and upon deepening the entrance to that river by con¬ 
structing jettees at the mouth of one of its passes, I abstained from any 
discussion of the question of applying the jettee system to improving the 
entrance, as certain information, important in the final treatment of the 
subject, had not then been collected by Captain Howell. This comprised 
certain soundings from the bars of the Southwest and South Passes out 
seaward several miles, as well as other data, including a carefully-prepared 
plan and estimate of the cost of applying the jettee system to those two 
passes. 

All the results of the soundings connected with the bar of the South¬ 
west Pass have been received, and the most important of those, relating 
to the South Pass bar, and I beg leave to present some views upon the 

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2 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

subject, which necessarily assume the form of a review of what has been 
advanced by others. 

The important fact developed by the soundings recently made by 
Captain Howell relates to the depth now existing in the Gulf, just sea¬ 
ward of the mouths of the river. Taking the maps and profiles exhib¬ 
iting the depth as it existed in 1838, and recognizing the fact that the 
bar of the Southwest Pass has advanced since 1838 at the rate of about 
300 feet in a year, the jettee advocates have taken it for granted that the 
bars of the Southwest and other passes are now being extended in a 
part of the Gulf where the water is very deep, into which very deep 
water the jettees will push the obstructing part of the bar, which they 
erode, and also the material which forms the bar’s annual growth, and 
will thus easily maintain the depth of 25 feet, or greater, on the bar. 
But during all this time, since 1838, the river water, in addition to 
pushing the bars annually into the Gulf about 300 feet, has been depos¬ 
iting the greater part of the earthy matter it held in suspension, upon 
the bottom of the Gulf, beginning at the outer edges of the bars, and 
extending seaward between five and ten miles. This is not the earthy 
matter forming the bar, which the river water pushed along its bed un¬ 
til it reached the sea, but the earthy matter which forms the bottom of 
the Gulf for several miles seaward of the bars. 

Upon examining the map of the recent soundings of Captain Howell 
we find that, at the crest of the present bar of the Southwest Pass, there 
was, in 1838, a depth of 125 feet. We also find that where, in 1838, at 
the distance of 13,000 feet seaward of the bar, there was a depth of 145 
feet, there is now only a depth of 45 feet, (this point, where the depth 
is only 45 feet, being 3,000 feet seaward of the crest of the bar.) We 
find, further, that this bar is now being extended annually into the Gulf 
in water not so deep as the bar was advancing in in 1838. We find, also, 
that from the crest of the present bar to a depth of 100 feet the distance 
is now 8,000 feet; whereas,in 1838, from the crest of the bar to 100feet 
depth the distance was 4,700 feet; and we find, further, that from this 
point, where there is now 100 feet depth outward, for the distance of 
some eight or ten miles, the deposit made on the bottom of the Gulf, be¬ 
tween 1838 and 1873, is between 60 and 70 feet thick, or at about the 
rate of 2 feet per year. 

The mean annual amount of earthy matter in suspension carried to 
the Gulf by the Mississippi Kiver would cover an area of one square 
mile 241 feet thick. The Southwest Pass carries to the sea 0.34 part of 
this, and the larger portion of this mass is deposited on an area about 
two and a half miles wide and ten miles long. If all were deposited on 
this area it would form a deposit 3.26 feet thick. We have found, by 
the comparison of soundings, that over much the greater portion of the 
area the deposit is, on an average, 2 feet thick. The other portions of 
the suspended matter are carried ten or twenty miles, or even greater 
distances, further seaward, and also over greater widths than the mean 
I have used of two and a half miles. 

The opinion has been expressed by some engineers, in discussing the 
question of the application of the jettee system to the entrance of the 
Mississippi Biver, that the earthy matter of the bar and the earthy mat¬ 
ter held in suspension will be pushed out by the jettees so far that a 
littoral current, which is supposed by them to exist outside the bar, will 
carry this earthy matter away from the approach to the entrance. 

They seem either to forget or not to know that the greater part of the 
earthy matter held in suspension which is brought to the crest of the 
barn .i§. deposited bet ween the crest and points from five to ten miles 



IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 3 


directly seaward of them, and in the direction of the mid-line of the 
pass prolonged, which direction the current of the river maintains after 
it passes over the crest of the bar. 

If there was a littoral current of force sufficient to carry off any 
large quantity of this earthy matter, it would not have been deposited 
where it is now, and always has been, found. What has been said re¬ 
specting the recent soundings of Captain Howell exhibits this fact 
clearly. 

Further, upon examining the horizontal curves of equal depth on 
Captain Howell’s recently prepared map, going out as far as a depth of 
350 feet, we find that, from the crest of the bar to 100 feet depth, the 
greatest amount of deposit is made east of the axis or mid-line of the 
pass prolonged ; between 300 feet and 200 feet depth the greatest amount 
of deposit is made west of that line, and between 200 and 350 feet the 
greatest amount of deposit is made east of that line. Further, the in¬ 
vestigations into the currents made under Captain Talcott’s direction in 
1838 for the very purpose of ascertaining whether there was a littoral 
current, failed to detect its existence off any of the passes, the investi¬ 
gations in the case of the Southwest Pass extending seven miles sea¬ 
ward of the bar. 

The very shape of the delta is indicative of the absence of such 
current. Its increase in the direction of the months of the passes, 
and the existence of such areas of water as Blind Bay, Garden Island 
Bay, and East and West Bays, which would have been gradually filled 
in the course of the delta formation by deposit if such current had ex¬ 
isted, all point to its absence. 

The investigations carried on under my direction, in 1851 and subse¬ 
quently, show, with sufficient precision for any application to engineer¬ 
ing purposes, what the nature, direction, and force of the currents of 
the Gulf are (as distinguished from the currents of the river-water) 
off* the mouths of the Mississippi Biver. The effect of these currents 
upon the passes, their mouths and bar-formations, was discussed in the 
chapter of the report treating of that subject, and was fully considered 
in preparing the part entitled u Experimental theory of the formation 
of the bars.” 

These Gulf-currents are due to changes of the level of the Gulf, owing 
to tides and winds, and their resulting effect (together with that of the 
waves) upon the passes, their bars, and their sea-deposit, are all shown 
by the actual position of the passes and the conditions existing at their 
mouths; and there is no ground whatever for anticipating any modifica¬ 
tion of their action by building jettees; they will neither carry away 
from nor bring to the bar or the bottom of the Gulf any more earthy 
matter if jettees should be built than they do now, and their influence 
upon the jettee system is absolutely nothing. 

The prominence which has recently been given to the effect of a lit¬ 
toral current in connection with the jettee system is derived entirely from 
the influence attributed to it in the case of the improvement by jettees 
of the Sulina branch of the Danube; and because the South Pass is the 
smallest of the passes of the Mississippi Biver, it seems to be assumed 
that the conditions of the Sulina will be found at the South Pass. 

The Sulina branch of the Danube carries off one-fourteenth part of 
the volume of that river, and its mouth lies about midway between the 
mouths of the two main branches, the mouths of the Kilia branch being 
about fifteen or twenty miles north of it, and of the St. George branch 
being about the same distance south of it. The Kilia branch carries off 


4 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

two-thirds of the volume of the Danube, the St. George one-third, from 
which the Sulina takes its supply. 

The discharge of the Danube, in flood, is about 333,000 cubic feet per 
second; in low water, about 111,000 cubic feet per second. The dis¬ 
charge of the Sulina, in high water, is about 24,000 cubic feet per 
second; in low water, about 8,000 cubic feet per second. 

The South Pass of the Mississippi discharges, in high water, about 
83,000 cubic feet per second, and in low water about 25,000 cubic feet 
per second, and carries to the sea ten times as much earthy matter as 
the Sulina branch, almost the same quantity as the Kilia branch, and 
nearly two-tliirds as much as the whole Danube. 

The small quantity of earthy matter carried to the sea by the Sulina 
branch, joined to the fact of the existence of a littoral current across its 
mouth, were the two causes which, in the judgment of Sir Charles Hart¬ 
ley, the engineer of the commission for the improvement of the mouths 
of the Danube, made the jettee system peculiarly applicable there and 
led to its success, the jettees causing the earthy matter in suspension to 
be carried out into the littoral current, which then carried a large part 
of it away. 

This littoral current did not extend to the bottom of the sea or sur¬ 
face of the bar, but merely a few feet below the surface of the sea. It is 
stated that there is no tide in the Black Sea, the variations of the level 
of its surface being due to winds. At the mouth of the Danube the 
northeast winds, being not only the prevalent wind but nearly inces¬ 
sant, causes a littoral southerly current along the west shore, the mouths 
of the Danube being, in a northerly extension of the Black Sea, about 
one hundred and twenty-five miles wide. The discharge of the Kilia 
branch, on its way to the Bosphorus, after it has dropped its earthy mat¬ 
ter, passes across the mouth of the Sulina branch and strengthens the 
littoral current derived from the wind. 

Let us examine a little more closely into the facts of the Sulina im¬ 
provement. I find, by a comparison of the Russian map of 1829, and 
the English map of 1857, of and off the Sulina mouth of the Danube, 
(see Minutes of Proceedings Institute Civil Engineers, vol. xxi, L861-T>2,) 
that the old (1829) inside 12-foot curve of the bar did not progress sea¬ 
ward during that time, but receded 250 feet, and worked to the north¬ 
ward that extent or more. 

The old outside 12-foot curve (of 1829) in some places did not move 
out, in others moved eastward 200 or 300 feet, and in others twice as 
much. Its mean movement is 350 feet in 28 years, or 13 feet per year. 
The outside 15-foot curve on the old channel line, for the full width of 
the mouth of the river, did not move out appreciably. South of the 
natural channel the 15-foot curve moved out 800 feet in the twenty-eight 
years; north of the natural channel it moved out 500 feet in the twenty - 
eight years, the mean advance of the curve iu the twenty-eight years 
being something less than 600 feet, or about 22 feet per year. The mean 
outward movement of the 30-foot curve, however, is 3,000 feet in twen¬ 
ty-eight years, or about 110 feet per year. It is evident, then, that 
this crest of the Sulina bar remained essentially stationary, so far as 
any outward movement is concerned, during the twenty-eight years 
that elapsed between the two periods of survey. 

Further, the sea-shore line at the mouth of the Sulina is also station¬ 
ary, and we do not find any recent delta formation at its mouth. The 
characteristic of a delta-forming river is the constant annual extension 
of the shores at its mouth, the constant advance of the crest of its bar 
and of the whole bar, and the constant annual advance of the deep 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 5 

channel inside of and behind the bar. None of these characteristics 
are found at the mouth of the Sulina, which has long since ceased to be 
a delta-forming river. 

Eut the Sulina bar has many of the characteristic conditions existing 
at the mouths of the little rivers emptying into the northern lakes, 
where the Engineer Department has constructed harbors by using two 
piers or jettees. Thus, at Chicago there was a depth of only two or 
three feet on the bar at the mouth of the Chicago River. Parallel piers 
were built there, and at the first spring flood following their construc¬ 
tion a channel of considerable depth was scoured out. That was the 
commencement of the present fine harbor at that place. There is a 
shingly shore north of Chicago, and hence large annual accretions be¬ 
hind the north pier. The Chicago River is not muddy. 

There is another distinguishing difference of characteristics between the 
Sulina bar and the bar of a delta-forming stream. During the flood 
condition of the Danube the crest of the bar of the Sulina is deepened 
by the current, but is shoaled again when the flood subsides. On the 
contrary, the crests of the bars at the mouths of the Mississippi are 
never materially deepened by the river flood, but the annual extensions 
of the bars seaward then take place, and these extensions or additions 
to the bars are as shoal as the crest, the shoalest part. 

The quantity of earthy matter held in suspension and thus carried 
to the sea by the Sulina is also very small, compared to that of the South 
Pass of the Mississippi River, the smallest of the passes. In the case of 
the Sulina we perceive the efficacy of the littoral current moving south¬ 
ward ; that is, toward the outlet of the Black Sea, the Bosphorus. It 
carries off the earthy matter while it is held in suspension, but does not 
remove the deposits made by the Sulina ; for, as before stated, the lit¬ 
toral current does not extend downward to the sea bottom or shoal, but 
is found at the surface of the sea, and for a few feet below the surface, 
consequently it has no influence at all upon the earthy matter pushed 
along the bottom of the Sulina by its fresh-water volume, which moving 
matter is deposited where the fresh w ater rises on the salt. 

Now, the earthy matter held in suspension by the Mississippi River 
is mainly kept in suspension by the horizontal and vertical irregulari¬ 
ties of the bed, (see page 139, Report on Mississippi River,) which con¬ 
stantly stir it up so long as these irregularities exist. When these ver¬ 
tical and horizontal irregularities diminish, the quantity of suspended 
matter diminishes, some of it falling to the bottom ; and when these ir¬ 
regularities cease altogether, the greater part of the suspended earthy 
matter begins to fall to the bottom. In the vicinity of New Orleans 
the material thus dropped, which is drifting along the bottom, is the 
same kind of material as the sediment held in suspension, no coarse 
material being carried or pushed by the river past this point. Below 
New r Orleans the course of the river varies but little, and its cross-sec¬ 
tion becomes much more uniform than above; as a consequence the 
sediment bills to the bottom m much larger proportion in this section 
of the river than above. 

The horizontal and vertical irregularities of the bed cease almost en¬ 
tirely where the Southwest Pass begins to widen, 7.3 miles from the crest 
of the bar, and from this point seaward the suspended sediment falls to 
the bottom at a nearly uniform but slowly decreasing rate for twenty or 
thirty miles. The greater part of it is deposited on the bottom of the 
Gulf between the crest of the bar and a point about ten miles seaward. 
Some of it is carried further seaward. A part, as above stated, is 
dropped upon the bar, commencing where the pass begins to widen, and, 


6 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


during the high-water stage of the river, is pushed along, with the 
other earthy matter there, to the crest of the bar, and forms part of the 
material which extends the bar annually into the Gulf. When the river 
is in a low stage the earthy matter dropped on the bar remains there, 
subject only to the feeble Gulf currents of the salt water, which then 
flow in and out over the bar underneath the fresh water surface-current. 

It is perceived from this explanation that there are two separate, dis¬ 
tinct bar formations at the mouths of the Mississippi River$ the one 
formed by the earthy matter pushed along the bottom of the river and 
bar, which is the formation known by every one as the bar , the obstruc¬ 
tion to navigation; the other formed by that part of the earthy matter 
held in suspension, which lies where it was dropped outside, or seaward, 
of the first-described deposit, or bar. 

Although this last deposit does not, itself, obstruct navigation di¬ 
rectly, yet it plays a very important part in causing the obstruction, 
since it converts the deep water of the Gulf into shoal water, and thus 
prepares the bed upon which the annual advance of what is usually 
termed the bar, is made. The one bar is formed by being superimposed 
upon the other. 

In the case of the Sulina improvement, the annual seaward accretions 
to the crest of the old bar, made by the earthy matter pushed along 
the bottom of the river, were always very small, and, as the jettees now 
throw the suspended earthy matter well into the littoral current, a large 
part of it is carried away from the mouth of the stream, and hence the 
shoaling due to the deposit of the remainder (which is not carried away 
by the littoral current) is much slower than formerly. The earthy matter 
pushed along the bottom of the river appears to have always been so 
small in quantity, as not to have had any controlling power over the 
bar formation. It is now carried by the action of the jettees (which 
extend into deep water) into comparatively deep water, and adds some 
additional material to the deposit made by the suspended earthy mat¬ 
ter. 

In the case of the mouths of the Mississippi River, even at the mouth 
of the smallest pass, the quantity of both kinds of deposit matter is 
enormous, and there is no littoral current to carry the suspended matter 
away. Even if there were at the mouths of the Mississippi a littoral cur¬ 
rent of the force of that existing at the Sulina mouth of the Danube, 
(the most careful observations have, however, failed to detect the exist¬ 
ence of any at all,) it would be utterly impotent to cause any material 
modification of the bar-formations. 

It may be remarked here that the distance which the current of a 
delta river extends into a tideless or nearly tideless sea depends more 
on the volume of the river than the velocity of the current. The veloc¬ 
ity of the current being the same in the one case with a small volume, 
and in the other with a large volume, in the first case the current will 
soon be neutralized, while in the other it will extend for miles into the 
sea before it is brought to rest. 

From the foregoing it is apparent that the Sulina bar of the Danube 
has no resemblance to the bars at the mouth of the Mississippi River, 
and that what they have been dealing with in the improvement of the 
Sulina is a bar or shoal derived chiefly from the deposit of earthy mat¬ 
ter held in suspension and not earthy matter pushed along the bottom of the 
bed of the Sulina. 

A very important question connected with the jettee system is the rate 
at which the bar will advance under the influence of jettees. This, it 
seems to me, is not difficult of solution. The principles which should 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 7 


guide the application of this system are enunciated in that portion of 
the report of Humphreys and Abbot upon the Mississippi River, sub¬ 
mitted August 5, 1861, which treats of the mouths of the river, 
especially the sections under the captions of u experimental theory of the 
formation of harsf and u recommendations for improving the navigation 
at the months.” 

The following is extracted from the latter section, pages 455 and 456: 

The development of the laws which govern the formation of the bars has removed 
all uncertainty as to the principles which should guide an attempt to deepen the 
chaunels over them. The erosive or excavating power of the current must be increased 
relatively to the depositing action. This may be done either by increasing the abso¬ 
lute velocity of the current over the bar, or by artificially aiding its action. To the 
first class of works belong jettees and the closure of lateral outlets ; to the latter, stir¬ 
ring up the bottom by suitable machinery, blasting, dragging the material seaward, 
and dredging by buckets. These plans are all correct in theory, and the selection from 
them should be governed by economical considerations. 

If the excavating power and depositing action of the Southwest Pass had been 
equal when the yearly advance of the bar was 700 feet instead of 333 feet, the least 
depth upon it would have been 21 feet. This increase of excavating power may be 
obtained by constructing two converging jettees, beginning where the depth of 22 feet 
is found, aud extended to that depth outside the crest of the bar, which would give 
them a length of about 2.5 miles. The experience gained in the piogress of the work 
should determine where the convergence should cease and the parallelism begin. The 
erosive action should be aided by first dragging and scraping the hard portions of the 
bar. The depth of 21 feet thus obtaiued must be maintained by the annual extension 
of the jettees 700 feet into the Gulf, and the reduction of the mud-lumps by suitable 
machinery whenever they begin to appear. 

But it appears to be desirable to go somewhat more into detail in this 
explanation. Accordingly, taking the Southwest Pass as a model, 
and taking the dimensions of the careful survey of 1838, we find that it 
has a mean width of 1,200 feet and a mean depth of about 60 feet. 
About seven miles before reaching the crest of the bar the channel 
begins to widen and the depth to decrease, and they continue to do so 
until at the crest of the bar the width is 11,500 feet, and the mean depth, 
from having been 60 feet, is but 11.5 feet. 

An addition of 338 feet is made to the bar every year along the whole 
line of the crest, 11,500 feet long. This is the annual extension into the 
Gulf. This addition or extension has the same mean depth of water on 
it as the crest, 11.5 feet. If we go back from the crest of the bar 
toward the point where the pass begins to widen, we shall find a depth 
of 21 feet in the channel-way, where it is about 6,000 feet wide. 

The same bulk of earthy matter is, in a series of years, added to the 
bar annually, and if it be added to it on a line 6,000 feet long, instead 
of 11,500 feet long, the seaward length of the addition must be about 
twice as great, (the depth of water upon which this addition is made 
being substantially the same in each case;) that is, the bar, instead of 
being extended 338 feet into the Gulf annually will be extended twice 
that distance or about 700 feet. 

If we refer to the channel where it is 25 feet deep, we find the width 
to be about 4,000 feet; and the mass of the annual addition to the bar 
being the same, the annual extension on a front of 4,000 feet, instead of 
being 338 feet, will be about 1,000 feet, and this will be about the annual 
extension of the bar for a depth of 25 feet if the jettees are suitably 
arranged for that depth. If they are at a greater distance apart, the 
depth will be less than 25 feet. If they are at a less distance apart, the 
depth will be greater, aud, the addition to the bar being formed on a 
less front than 4,000 feet, will have a greater annual extension than the 
bar formed on that front. So that in applying jettees to permanently 


8 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


deepening the bar of the Southwest Pass to 25 feet, we must expect an 
annual extension of the bar of about 1,000 feet. 

Examining the map of the bar, we find that the horizontal distance 
between the part of the channel (inside the crest) where the depth is 
25 feet to the point in the channel (inside the crest) where the depth is 
21 feet is about 4,000 feet, and we have every reason to conclude, and 
not one reason for a contrary conclusion, that if the jettees are not ex¬ 
tended after obtaining the depth of 25 feet, in four years 7 time the bar 
will have extended into the sea about 4,000 feet, and, following the law 
under which it has heretofore been formed, the depth on its crest will be 
21 feet ; that is, the bar-accretions will be made on a slope rising at the 
rate of 1 foot per every 1,000 feet of accretion. 

The conclusion is inevitable: the jettees must he extended annually at the 
same rate that the bar is advancing , if ice intend to maintain permanently the 
same depth upon the bar. 

If the depth to be maintained is 27 feet at low water, or 28 feet at 
high water, it will be found by a similar process that the annual ad¬ 
vance will not be less than 1,200 feet. 

The jettees may be so arranged as to cause a greater depth than the 
one required, and thus obviate for a time the necessity of their annual 
extension into the Gulf, but such an arrangement will entail a propor¬ 
tionate by greater first cost in their construction. The final result as to 
cost and depth will be the same whether the jettees be converging or 
parallel, and the parallel has therefore been assumed as the model in 
this discussion. 

Some engineers have adopted the opinion that the jettees, by increas¬ 
ing flie strength of the current largely, will carry the earthy matter 
forming the bar so far out and into such deep water that there will prac¬ 
tically be no necessity for extending the jettees after the desired depth 
has been once obtained. This view is derived from the supposition 
that the bar is formed by the check which the current of the river-water 
receives in entering the Gulf; which check, it is said, reduces its veloc¬ 
ity so much that the earthy matter, carried in suspension by the river- 
water, is dropped at once into the Gulf and forms the bar. This was 
the opinion usually held by engineers in former times, but was not based 
upon any measurement of .the currents or careful observation upon 
them. It was known that the river-current was brought to rest in the 
sea, and it was assumed that at the point where it apparently entered 
the sea, (that is, where its banks were salt-water instead of earth,) a 
sudden and great reduction in the strength of the current took place, 
much greater than occurred at any other point of its prolongation into 
the sea. But those who have carefully examined the mouths of the Mis¬ 
sissippi River, or who have examined the series of current observations 
made there under my direction, perceive that there is no material check 
to the river-current as it enters the Gulf, and that it requires exceedingly 
nice measurement to detect any change in this velocity over long dis¬ 
tances. In fact, the current of the river is retarded at a very slow 
rate from the point where the pass begins to widen, seven miles inside 
the crest of the bar, until it is brought to rest, some twenty miles or 
more seaward of the crest, at high water, and some ten miles or more 
at low water, making the whole distance before it is neutralized twenty- 
seven miles or more at high water and seventeen or more in low water. 
And along those distances of twenty-seven miles in high and seven¬ 
teen in low water, it drops the suspended earthy matter at a nearly 
uniform but slowly-decreasing rate. 

These being incontrovertible facts, the questions next occur, where 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 9 


does the material come from that forms this great deposit which adds 
annually 338 feet to the bar of the Southwest Pass, with a depth upon 
it of 134 feet at low water? and why is this material, wherever it may 
come from, deposited in juxtaposition to the old bar on the seaward 
side ? 

Two observed facts put together answer these questions clearly. The 
first, the ascertained fact, already mentioned, that throughout the 
whole course of the river there is a mass of earthy matter pushed along * 
the bottom of the river (not suspended in the water) moving at a much 
slower rate than the current of the river. At the mouth of Red River, 
two hundred miles above New Orleans, this material was chiefly small 
gravel and coarse sand ; not far below Red River, coarse sand and small 
balls of blue clay; still lower down, coarse sand; and in the vicinity of 
New Orleans, at all stages of the river, chiefly sand and earthy matter, 
the same kind of sediment as that found in suspension at that point, 
the sand being very fine. No coarse material passed this point of the 
river. 

The second is the ascertained fact that, where the fresh-water current 
of the river meets the salt-water of the Gulf, the fresh water rises upon 
it, and creates a dead angle of salt-water on the seaward side of the bar; 
and when the earthy matter pushed along the bottom of the river arrives 
cit this point, the fresh water having risen from it, there is no longer any 
pushing force to keep the earthy matter in motion. It remains in the 
still salt-water, forming an accretion to the bar. Its upper surface lies 
along the slope, on which the fresh water moves upward upon the salt 
water, which repeated measurements upon the bar of the Southwest 
Pass prove to be (on that bar) a slope of one foot in a thousand. It can 
make no difference whether the river-current be moving at the rate of 
4 feet, 3 feet, or 2 feet per second, when it reaches the point where it 
rises on the salt-water, the matter pushed along the bottom will come 
to rest in the still salt-water substantially at the same point. 

We have seen that no coarse material is carried or pushed by the 
river past New Orleans, the drifting material there being of the same 
character as the suspended matter. Fifteen miles below New Orleans a 
marked change takes place in the river; its course to the sea varies but 
little, and its cross-section becomes much more uniform than above, and, 
as a consequence, the suspended matter falls to the bottom in larger 
proportion than above New Orleans. The sedimentary matter thus 
dropped to and pushed along the bottom of the river during high water 
to the point where the pass begins to widen, and thence to the outer 
crest of the bar, forms a part, but not the whole, of the annual accretion 
of the bar. That portion of the suspended sediment dropped in high 
water on the seven square miles of the bar, and swept to its outer crest, 
forms another part of its annual accretion. 

Respecting the character of the material composing this bar, George G. 
Meade, one of Captain Talcott’s principal assistants, who had charge of 
that portion of the survey of 1838 comprising the Southwest and South 
Passes, says, of the bar of the Southwest Pass: 

The bar is composed of mud and sand, the matter held in suspension by the river- 
water. * * * * * * Within and without the shoal the bottom is soft 
mud of a bluish and yellow tint, having a large proportion of alumine. Immediately 
on the shoal the bottom is harder, and has a greater proportion of sand. 

Respecting the South Pass he states: 

The bottom is generally sand interspersed with spots of soft mud. The bottom on 
the bar is principally fine gray sand, mixed with a small proportion of mud. Without 
the shoal the soft yellow andhlue mud of the passes is found. The character of the 
bar is sand, as it is of the passes and of the adjacent shoals. 


10 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Let us see what, changes, if any, would take place in the amount of 
suspended earthy matter dropped between the point where the pass 
begins to widen and the crest of the bar, if jettees were constructed so 
as to give 28 feet water. 

Half-way between the point where the pass begins to widen and the 
outer crest of the bar, we find (map of 1838 taken as the model) in the 
middle of the channel a depth of 28 feet at high water for a width of 
1,800 feet. Jettees properly constructed from this point to a similar depth 
outside the crest of the bar would give the required depth of channel- 
way. 

It has already been pointed out that the greater part of the sus¬ 
pended earthy matter begins to fall regularly to the bottom as soon as 
the horizontal and vertical irregularities of the channel-way cease; and 
if the volume of discharge passes between straight jettees of uniform 
distance apart, with a uniform cross-section throughout their length, we 
have the conditions favorable to the falling of the suspended matter to 
the bottom. 

Now, all the earthy matter pushed along the bottom of the river above 
the point where the pass begins to widen, and all that dropped below 
that point for one-half the length of the bar, (where the jettees are sup¬ 
posed to begin,) will be pushed along the bottom between the jettees to 
the outer crest of the bar; and all the suspended earthy matter that 
drops to the bottom throughout the length of the jettees (one-half the 
length of the bar) will also be swept there. How much, it will be 
asked, would this last quantity (the suspended earthy matter dropped 
to the bottom throughout the length of the jettees) differ from the quan¬ 
tity dropped on the last or outer half of the bar, if there were no jet¬ 
tees ? The difference is indicated by the difference in their mean velo¬ 
cities so far as the quantity of deposit is dependent on the mean velocities , 
and should be inversely as those velocities; that is, the quantity drop¬ 
ped on the same length would be between one-fifth and one-sixth less 
between the jettees than on the lower half of the bar. Compared to the 
whole quantity dropped on the bar, it would be one-eighth less. 

It has been recently stated by a civil engineer, in a pamphlet concern¬ 
ing the improvement of the mouths of the Mississippi River by jettees, 
that the amount of sedimentary matter carried in suspension by the 
Mississippi River is in exact proportion to the velocity of its current; 
and that as a given velocity of current will keep in suspension a cor¬ 
responding quantity of solid matter at a less velocity, a certain portion 
of it will be dropped. To illustrate this he states that— 

When the Bonnet Carr6 crevasse occurred, the river below it (.107 feet of depth) was 
shoaled up 31 feet, because the volume of water in the river, being lessened by the 
crevasse, was no longer sufficient to maintain the normal current in a channel large 
enough to carry the entire river; consequently the current below the crevasse slack¬ 
ened, and the excess of load was dropped in the channel until the bottom was filled up 
31 feet with the deposit. This reduction of channel was sufficient to re-establish the 
current and prevent further deposit. 

The first statement is in direct conflict with the results of the long- 
continued measurements made upon the quantity of earthy matter held 
in suspension by the Mississippi River at Carrollton, near New Orleans, 
and at Columbus, twenty miles below the mouth of the Ohio, one of the 
chief objects of which was to determine this very question, whether any 
relation existed between the velocity and quantity of earthy matter held 
in suspension. These results prove that the greatest velocity does not 
correspond to the greatest quantity of earthy matter held in suspension ; 
on the contrary, at the time of the greatest velocity of the current at 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 11 


Carrollton the riv r er held in suspension but little more sediment per 
cubic foot than when the velocity was least. When the quantity of 
earthy matter held in suspension was greatest the velocity was two feet 
per second less than the greatest velocity, the quantity of earthy mat¬ 
ter in the one case being three times as great as in the other. We find 
at another time, when the velocity was one-half the greatest velocity, 
the quantity of earthy matter held in suspension was double in amount. 

At Columbus we find similar conditions existing. At the time when 
the greatest quantity of earthy matter was held in suspension, the 
velocity was less than one-half the greatest velocity; and at the time of 
the greatest velocity the quantity of earthy matter in suspension was 
one-half the maximum quantity. Again, we find a time when the quan¬ 
tity of earthy matter in suspension was nearly the same as the maxi¬ 
mum, the velocity being less than one-third of the greatest velocity. 
Again, we find the quantity of earthy matter in suspension the same, 
the velocity in the one case being 6.75 feet per second, and in the other 
1.5 feet per second. 

The following tables, illustrating what has just been said, have been 
prepared from the Report on the Mississippi River. The figures given 
express the conditions existing not only on the one day noted, but on 
several successive days. 

During the whole period of observation the river bed remained un¬ 
changed. It will be noticed that even the maximum amount ef sedi¬ 
ment in the river water is a very small quantity compared to the mass 
of water, it being by weight in the proportion of one ounce of fine 
earth to six hundred and eighty ounces of water; aud by volume one 
cubic inch of earthy matter to one thousand three hundred and sixty 
cubic inches of water. 

It is to be remarked that the investigations respecting the sediment in 
suspension show that the quantity depended on whichever river the vol¬ 
ume of discharge was at the time chiefly derived from. 

. 1.— Carrollton, 1851. 


Date. 


February 20. 

March 20. 

April 15. 

May, (last week of).... 
June 20. 

July 10 to 30. 

August 1 to 20. 

September 8. 

October and November 

December. 

January 20, 1852. 


Weight, in grains, of 
sediment in one cu¬ 
bic foot of water. 

Mean velocities of 
river, in feet, per 
second. 

450 

5.5 

200 

6.2 

150 

5. 6 

100 

3. 75 

650 

4.3 

450 

4.8 

4501 

From 4. 8 ? 
to 3. 5 5 

300 

3.0 

100 

1.75 

175 

1. 85 

400 

2. 75 


Remarks. 


{ Change in velocity 
regularly decreas¬ 
ing, while matter 
suspended remains 
the same. 





















12 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


2.— Columbus, twenty miles below mouth of the Ohio, 1858. 


Date. 

Weight in grains 

of sediment in 

1 cubic foot of 

water. 

Mean velocity of 

river in feet per 

second. 

Remarks. 

April 1. 

300 

7. 00 


April 10. 

300 

5. 25 


April 25. 

450 

7. 25 


May 1. 

300 

7. 50 


May 10. 

300 

5. 75 


May 22. 

160 

6. 75 


June 16. 

330 

8. 25 


July 16,17. 

650 

3. 75 


August 2. 

350 

4. 75 


August 9. 

250 

4. 00 


September 2. 

600 

2. 50 


September 9 to 23. 

200 

2. 25 

Uniform decreasein amonntof sediment 
the velocity remaining the same. 

October, (all of). 

200 to 100 

1.50 


The cross-sections both at Carrollton and Columbus remained un¬ 
changed during the observations. 

The statement concerning a deposit below the Bonnet Carre crevasse 
is also in direct conflict with ascertained facts. (See pages 387, 388, 
389, 390, and 393, Report on Mississippi River.) 

This statement concerning a deposit being formed below the Bonnet 
Carre crevasse was made just before the survey of the Mississippi Delta 
was begun, and was carefully investigated in the course of that survey. 
The subject had an important bearing upon the question of using outlets 
to reduce the floods. It was found there had been no deposit whatever 
below the Bonnet Carre crevasse, and that the bottom of the river 
there was composed of hard blue clay, of older formation than alluvion, 
and that the cross-section had unquestionably remained unchanged. 

Reference is also made in this pamphlet by its author to certain 
experiments by Prof. E. W. Hilgard, of the University of Michigan, 
who u has classified silts according to the different velocities at which 
they deposit,” as confirming the views expressed that the sedimentary 
matter carried in suspension by the Mississippi varies precisely with 
the velocity of current. The classified table of Professor Hilgard gives 
the relative velocities created in a mechanical contrivance made for 
test-purposes in a laboratory, in which coarse sand is dropped at a 
certain velocity of the machine, which may be represented in nature as 
a current of about 2J inches per second; the finest sand when the 
current is 0.3 of an inch per second ; the coarsest silt when the velocity 
is 0.14 of an inch per second; the finest silt when the velocity is about 
0.02 of an inch per second. 

If these experiments of Professor Hilgard had any application to the 
Mississippi River, they would prove that there could not possibly be 
any addition to the bar, where it is added to every year with a current 
of 3 feet per second running over it and seaward of it; and they would 
prove that there could be no bar until the current of the river was 
reduced to a rate varying between 2J inches per second and 0.1 of an 
inch per second, that is, some fifteen or twenty miles further seaward 
than it is now. They would prove, also, that there could be no deposit 
in the Gulf just seaward of the bar, where there has been a deposit 70 
feet thick since 1838. It is unnecessary to pursue this subject further. 

But, it is said by some, the construction of jettees will at least carry 

























IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 13 


tlie earthy matter held in suspension so far seaward that the thickness 
of the deposit formed by this matter on the bottom of the Gulf will be 
largely reduced. It seems to me that this opinion has been adopted 
without careful consideration. Taking the Southwest Pass as a model, 
an examination of the processes going on there will make it apparent that 
the earthy matter in suspension will, in the event of the application of 
parallel jettees to deepen the bar of that pass, be carried further sea¬ 
ward of the crest of the bar than it is now carried by just the length of 
the jettees built. If these are intended to give 21 feet at low water, the 
earthy matter in suspension will be deposited over a length about two 
and a half miles longer seaward; that is, instead of being deposited on 
a length of ten miles, it will be deposited on a length of twelve and a 
half miles; if 25 feet depth is to be had, that matter will be deposited 
on a length of about thirteen and a half instead of on a length of ten 
miles. But the width of the area on which it will be deposited next 
to the outer crest of the bar will be proportionally diminished at pre¬ 
cisely the same rate. Instead of being 11,500 feet wide there, it will be 
one-half that width in the case of 21 feet depth, and one third that 
width in the case of 25 feet depth. The area of deposit, and conse¬ 
quently the thickness of deposit, will remain substantially the same. 

According to the measurements of Captain Howell, the annual ad¬ 
vance of the bar of the Southwest Pass during the past three years has 
been about 400 feet. The rate given in the report on the Mississippi 
River by Humphreys and Abbot, 338 feet, was deduced from a careful 
comparison of Talcott’s large-scale map of 1838 with that of the Coast- 
Survey of 1851. A comparison of Captain Talcott’s map, from his sur¬ 
vey in 1838, with Captain Howell’s map, carefully prepared from sound¬ 
ings in December, 1873, and January, 1874, shows that the bar has 
advanced into the Gulf between the dates of those surveys nearly 
11,000 feet. 

Between these dates there were at least two years when the bar did 
not advance appreciably; they were the two great drought-years of 1855 
and 1850, which prevailed all over the country. In 1855, there was no 
high water at all. The river at New Orleans remained in low condition 
during the whole year, rising but once for a brief period to about half 
the ordinary height attained annually. At no time during the year was 
there any river-water in contact with the bar, and there was no accre¬ 
tion to the bar. In 1850, there was more volume in the river than in 
1855, but there was no high water, and it is probable that the bar 
advanced but a few feet during that year, if it advanced at all. 

A comparison of the most recent measurements with those of 1838 
gives no reason for adopting any new rate of advance for the bar at this 
pass. 

I have prepared an estimate of the cost of applying jettees to the 
Southwest Pass bar to obtain 27 feet at mean low water, or 28 feet at 
mean high water, the structures to extend down to the full depth of 28 
feet at high water. The cost is $7,000,000. 

If the jettees were simply built upon the surface of the bar, and not 
extended downward, their cost would be about one-half that sum. This 
mode of construction has been suggested by some engineers, and would 
be suitable if a long time were allowed for the erosion of the channel- 
way to the required depth. But this erosion must take place in a short 
time, and must be controlled by the jettee-structures. Hence the neces¬ 
sity of their being carried down to the depth of the intended channel. 

The annual cost of maintaining the depth by extending the jettees, 
according to my estimate, will be about $1,000,000, which, considered as 


14 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


interest at 6 per cent, per annum, represents a capital of $10,000,000. 
This, added to the first cost of my estimate, gives $23,000,000 for the 
expense to the Government of securing a permanent depth ol 27 feet at 
mean low water. 

To secure the same depth by constructing and maintaining a canal 
will cost $13,000,000. 

Respecting the practicability and cost of the canal, it is incumbent 
upon me to say that the officers comprising the board to which the sub¬ 
ject was submitted are among the ablest and most experienced in the 
Corps of Engineers. 

Regarding the practicability of the canal, I desire to make a brief 
extract from the report of Captain Talcott, a distinguished officer of 
the Corps of Engineers, transmitting the maps of his survey of 1838. 
He states that he bored to the depth of 40 feet on the line of the canal 
proposed by Major Chase, and found “firm bottom of sand mixed with 
mud, tenacious of water, and altogether such as would be considered 
favorable for excavating, and on which there would be no difficulty in 
securing a foundation for locks or structures of any kind.” 

SOUTH PASS. 

From the results of Captain Howell’s recent soundings on the bar of 
the South Pass and seaward of it, I have deduced that the advance of 
the outer crest of the bar since 1838 has been 3,900 feet or at the annual 
rate of 111 feet. Comparing the map of 1838 with the Coast Survey 
map of 1867, the advance was 3,220 feet, or at the annual rate of 111 
feet. Comparing the Coast Survey map of 1867 with his recent sound¬ 
ings, the advance is 680 feet, or at the annual rate of 113 feet. 

In preparing the Report on the Mississippi River, (in 1860-’61,) the 
advance of this bar was determined by comparing the Coast Survey 
map of 1851 with the map of 1838, and was found to be, in that time, 
(thirteen years,) 3,640 feet, or at the annual rate of 280 feet, which was 
the rate adopted. The printed comparative maps have been examined 
again and give the same result, but it is apparent that there was some 
error in the Coast Survey map of 1851, and the annual rate of 111 feet 
should be adopted for the advance of this bar, though there is still some 
uncertainty as to this rate. 

The mean width of the pass is 700 feet, but a less width for the jet- 
tees must be taken if a channel-way of suitable width with a depth of 
27 feet at low water is to be obtained. Assuming 500 feet for this 
width ; then, as the width of this bar where the annual accretion of 111 
feet is made is 3,000 feet, we shall have, with jettees 500 feet apart, an 
annual advance of 670 feet. 

The estimated cost of jettees to attain 27 feet depth at mean low 
water at this bar, the structures extending to and below that depth, is 
$4,150,000; the annual cost of maintaining this depth is $670,000, which 
annual expense represents a capital of $11,000,000, the two sums amount¬ 
ing to $15,250,000. 

To this estimate must be added the cost of dredging in those parts of 
the pass where there is less than 27 feet depth, and opening and keep¬ 
ing open the pass through the shoal at its head, on which there is now 
a depth of only 12 feet. 

Captain Howell estimates that the annual cost of this will exceed 
$100,000. The total cost to the Government of securing permanently a 
depth of 27 feet at low water by this pass will then be about $17,000,000. 

From my having had charge formerly of The survey of the Mississippi 

Note.—A ccording to Howell’s Map of 1874, received since this report was made, 

the length of the crest of the South Pass bar is 4000 feet. Its length according to 

Talcott’s Map of 1838 was more than 5000 feet. 

inn i _ ^ 1 « /I (\ a I fi •» n bnv 10(4 foot 111 -fcrnt- 


\ \ TT 









IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 15 


Eiver, made in pursuance of acts of Congress, one of the objects of which 
was to ascertain, by actual measurement and other experimental re¬ 
searches, in what manner the bars were formed and how the channels 
at the mouth through them could be deepened, I have felt compelled to 
present my views upon the jettee-system somewhat in detail, the more 
particularly as that portion of the report upon the physics and hydrau¬ 
lics ol the Mississippi Eiver was not as fully elucidated as it would have 
been under different circumstances, the report having been brought to 
a close in August, 1801, in the midst of all the disturbances of the 
early part of the war. 

As the minority report of the board on the Fort Saint Philip Canal 
contained much that was of the character of a review of the majority 
report, I should have reconvened the board and referred the minority 
report to it for consideration, but for the urgent requests made by mem¬ 
bers of Congress for the immediate transmission of the reports to the 
Secretary of War for submission to Congress. 

Having received from Lieut. Col. John Newton, the ranking officer of 
the majority, two carefully-prepared papers touching the minority report. 
I transmit them herewith, recommending his views to careful considera, 
tiou. 

I beg leave to recommend that these papers be transmitted to the 
House of Representatives with this report. 

Very respectfully, your obedient servant, 

A. A. HUMPHEEYS, 
Brigadier-General and Chief of Engineers. 

Hon. W. W. Belknap, 

Secretary of War. 


United States Engineer Office, 

New York, March 11, 1874. 

General: The board of engineers convened by Special Order No. 83, 
dated Headquarters Corps of Engineers, Washington, D. C., June 30, 
1873, to consider and report upon the plan submitted in compliance with 
a resolution of Congress, by Capt. C. W. Howell, Corps of Engineers, 
for a ship-canal to connect the Mississippi Eiver with the Gulf of Mexico, 
having already rendered their report, which has been made the subject 
of certain comments by a member who had dissented from the opinions 
of the board, it has seemed proper that, having signed that report, I 
should attempt to correct the misapprehension that there exists a 
material, if any, difference between the views of the board and those 
of the member alluded to upon the subject of the ship-canal. 

Before I have done I will state what the board did recommend, and 
what relation such recommendations bore to the whole project of Cap¬ 
tain Howell; but it is first necessary to a correct understanding and 
appreciation of the matter that certain points of the history of the 
proceedings of this board should be touched upon. 

1. The first report of the board, which it was directed should be in 
Washington by the 15th of last December, was written by one of the 
members after the adjournment of the board at New Orleans, which 
adjournment, it must be said, was hastened materially on account of 
instructions received by several of the members to repair to their works, 
in view of a supposed national exigency. The report thus prepared 
was sent to the different members for [their signature, and it received 



16 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


naturally a good many emendations, though in nothing affecting its 
essential matter. Owing to the close proximity of the loth of Decem¬ 
ber nothing could be done except to make these emendations in pencil, 
and so transmit it to Washington, with a letter explanatory of the 
necessity for this proceeding. 

Accompanying this report of the board was a minority report by the 
same member. Although these reports have been replaced by others 
from their several authors, yet as the author of the minority report has, 
in his later papers, referred to and quoted from his first report, I will 
exercise a similar right. 

With the majority of the hoard I concur in the opinion of the practicability of the 
work in an engineering point of view, but at the same time believe the execution to in¬ 
volve difficulties of a serious and unusual character for which engineering construc¬ 
tion yet made in this region, or in this country, offers no precedent. These difficulties 
are due to the character of the soil in which the work is laid. One of the important 
questions, and one which at the very first presented itself to the members of this board 
is the stability of the prism, i e., the self-maintenance of the bottom and sides of the 
canal excavation. No one of the experienced Louisiana engineers whom we have con¬ 
sulted has professed to be able to give a decisive answer on this. The subject is more 
particularly treated in the letter of Professor Forsliey, (appended.) 

Existing canals cut to depths of 6 feet through the swamps and ravines, and of 12 
or even 18 feet in high and well-drained marginal river soils (as the Barataria and La 
Fourche Canal) do not tell what will happen when we excavate 25 feet and more on the 
site of the proposed canal. I entertain no real apprehension that the prism cannot be 
ultimately made stable; but the process by which this result will come about I do 
not foresee nor define ; and I only remark how vague and uncertain must be the esti¬ 
mate which computes the accomplishment of this result at 50 cents pe$ cubic yard of 
excavation. 


And in summing up in that report, he further says: 

In conclusion I have to express the opinion that the ship-canal project requires 
further study before plans and locations and modes of operations can be fixed and a 
reliable or even approximate estimate can be made ; and I recommend : * * * * 

Third, that the survey of the ship canal be continued, and further studies as to locations 
and plans to be made; and in this connection one important experiment to make (in 
connection with multitudinous borings) would be a practical trial of excavation for the 
canal prism for a length of one or two hundred feet. 


Iu common with other members, I was strongly impressed, until the 
appearance of the report, which has been cited, that the dissenting 
member entertained an opposite view of the feasibility of excavating the 
trunk of the canal, which he based in part upon the'successful excava¬ 
tion of the North Sea Canal to a depth of 750 meters through an alluvial 
siol. 

The idea of this experimental prism was probably adopted from a 
suggestion by one of the signers of the report of the board, made prior 
to the visit to New Orleans. 

The preliminary report of the board had previously recommended an 
appropriation, among other objects, to be used for determining “the 
best locations for locks, and for the trunk of the canal.” The second 
report of the board again refers thelocation of the canal to the result of 
future examinations and borings. The author in his second minority 
report not only makes no mention of any apprehended difficulties in the 
excavation and maintenance of the trunk of the canal, but even ap¬ 
pears to fault the board with not determining the location of the canal 
until further borings and examinations should be made, and states : 


nor 


Neither observation of, and familiarity with, engineering works in Louisiana 
borings made by Captain Howell, suggest to me that anv material variation 
of its location will be suggested by further scrutiny of the substrata by boriu 


1 nr 


On the question ol maintenance ol the side-slopes of the prism of the 
canal theie have been appaieutly, on the part of the dissenting member, 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 17 


two changes of opinion, and oil the question of the necessity for further 
borings, one change of opinion, so that on these points at least the 
board cannot be said to have disagreed with him. 

The only difference between the dissenting member and the board, so 
far visible, is, he believes “ a more protracted and more comprehensive 
study is required to fix the location,” while the board urges additional 
borings and examinations to be made as a preliminary to the deter¬ 
mination of the best location of the canal. 

2. The foundations for the locks are diffusively treated in the minority 
reports of December G, 1873, and of January 29^ 1874. 

But there is no controversy on this score that I can discover between 
the board and the dissenting member, the board simply stating that the 
foundation can be laid by any one of several processes well known to 


engineers. 

3. One of the paragraphs of the minority report is so worded as to 
leave it to be inferred that the grillage designed in the project laid 
before the board was approved by them. This is a mistake; the grillage 
was never approved. 

4. The board of engineers, in their last report (printed) upon the canal 
project, arrive at the conclusion, “ more particularly and pertinently from 
the character of the borings made by Captain Howell,” that the construc¬ 
tion of the canal is entirely feasible. “But it is suggested, iu order to 
avoid beds and pockets of quicksand known to exist at some points iu 
this locality, that the precise line of the canal should not be decided 
upon until a more thorough examination of the substrata has been made 
by borings.” The board thinks that such an examination may indicate 
the necessity not only of adopting a curve or series of curves for the 
axis of the canal, but also of selecting other points of termini than those 
recommended by Captain Howell; also “one member of the board is in 
favor of locating the Gulf terminus to the northward, and consequently 
under the lee of Sable Point, and of securing the requisite depth of 
water into Isle au Breton Pass by dredging. This would naturally carry 
the river terminus nearer to Fort Saint Philip, and perhaps within suita¬ 
ble distance from the work to satisfy the requirements of a good defense 
without the erection of special works for that purpose. 7 

Before drawing my inferences, I invite particular attention to con¬ 
clusions 1,4, 7, and 8 of that report. The borings made by Captain 
IIow r ell being very few and far between, the board must have inferred 
the general character of the formation to be uuiform, the number of 
borings otherwise not being sufficient to predicate anything upon, and, 
least of all, to sustain the conclusion of the board that the construction 
and maintenance of the canal presented no extraordinary engineering 
difficulties. Notwithstanding the minority report expends much space 
and time in the attempt to show that the board thought there were 
material variations in the character of the formations, the variations 
which the board say do exist are limited areas or pockets of quicksand, 
and it might have been said of soft mud, which, for the economical con¬ 
struction of the locks and trunk of the canal, it were expedient to avoid. 
The minority report, though embracing a long quotation from the report 
of the board, neglects to instance the subject above, though this alone 
would furnish a sufficient reason for demanding further borings. The 
minority report, however, afterward concedes*this point in the following 
w ords: 


The mobility of “the find sand” where it exists, as it sometimes does, in strata, 
almost destitute of clay, may, indeed, enhance the difficulties of making the canal 
trunk, and getting through them to reach the lock foundation. * * * 

7 0 0 O 


H. Ex. 220-2 



18 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


This acknowledgment is as much as could be desired, 
reason 


5. 


Another reason for extended examinations was contained in the 
project of Major Warren ; this being the debouelie of the canal north of 
and under the lee of Sable Point. I send a tracing herewith, giving 
Major Warren’s line of the axis of the canal. Major Warren's idea of 
a radical change of the location of the axis was explained to the board 
long before that of Colonel Barnard or of General Beauregard, and the 
minority report mistakes when it asserts that the idea originated with 
the latter gentleman. This may not be a matter of importance, but it 
is the fact. 

It is clearly perceived, from this recapitulation, that an extensive field 
of investigation was laid out; the possible location of the canal along 
any line from Fort Saint Philip down to or even below the line selected 
by Captain Howell, would include not only an examination of the land, 
but likewise of a certain area of the bottom of the Gulf. 

6. If a line be adopted emerging into the Gulf north of Sable Point, 
which condition would carry with it the excavation in the water of a large 
portion of the trunk, no jettees would be necessary, and their cost, or a 
portion thereof, might be devoted, if considered necessary, to the con¬ 
struction of a breakwater against northeast and north storms. Ko pro¬ 
tection from southeast storms would be required, the land serving as 
breakwater against them. 

If the line of Captain Howell be selected, jettees would be required, 
and these should be spread apart at their junction with the land, and 
inclined toward each other at their seaward extremities, after the usual 
mode of forming a harbor with piers. The direction of the axis of the 
canal being northeast, besides the harbor itself, there would be a con¬ 
siderable lee on the outside of the piers for the protection of many ves¬ 
sels of moderate draught of water against southeast storms. These 
considerations of the protection of shipping against storms are not now, 
for the first time, thought of; they formed the subject of discussion by 
members of the board, and were so evident that it was not considered 
necessary to incorporate them in their report. Such, at least, was my 
view at the time. 

7. The necessity of fortifying the canal was likewise so evident that 
the board assumed it without discussion, and the only question in refer¬ 
ence to it to be found iu their report is whether the defense of the canal 
should depend upon existing works, or upon works specially constructed. 
!S T o doubt has ever been expressed of the advisability of attaching the 
defense of the canal to existing works, provided other important points, 
among which was the permanence of the banks, which might involve 
the security of the foundation of the lock, could be adjusted suitably. 
General Beauregard says in his letter: “ Its (the canal’s) location on the 
river should be under the protection of the guns of Forts Saint Philip 
and Jackson, due regard being had to the permanency of the river-bank .” 
(The underscoring is mine.) The permanency of the bank is the very 
point, for it has been represented to members of the board that encroach¬ 
ments upon one bank and fillings at the other are progressing at the 
bend, and in the neighborhood of Fort Saint Philip. This state of 
things requires careful investigation before deciding upon the location 
of the canal near that fort. 

8. The fact that the board had found it necessary to relegate the 
whole matter to the officer in charge for additional investigations before 
the location, even, of the canal could be satisfactorily settled, is a sufficient 
justification for their brief report, (if brevity iu such matters is ever to 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 19 


bo excused,) and for omitting* to discuss further details, most of which 
will probably be solved by the examination recommended. 

9. The line of canal recommended in the minority report furnishes a 
good lea against northeast storms, but not against southeasters. It 
would be ten and three-quarter miles long, of which eight and three- 
quarter miles would lie in the water. The navigation of a long, narrow 
channel, by vessels under the influence of side winds, would be difficult, 
owing to the constant tendency to drift upon the side of the excavation. 
I do not perceive how the cost could be less than that of Captain How¬ 
ell’s project, which is the most expensive of the various lines considered 
by the board; and, besides, our present knowledge of the bed of the 
Gulf in that locality is too limited to permit it to be assumed that the 
excavation of the trunk would be permanent. Investigations in the 
shape of borings , which the minority report will not join the board in 
recommending, appear to be necessary to solve the question. 

10. The minority report, to sustain its views, quotes with approval 
from a report of the late Colonel Abert, in reference to the canal project 
of the late Major Chase. The latter, in his report on a ship-canal, said : 

The obstacles presented to an easy entrance of the Mississippi by vessels drawing 12 
feet of water are productive of great injury to the commerce of New Orleans, and 
require to be promptly removed ; or, failing to be done, the construction of a ship-canal 
on the plan indicated by Major Buisson should be resorted to. 

No wonder that the expense of the project, ten millions, should have 
turned Colonel Abert’s views back to the methods of improving some 
one of the passes, to ascertain whether 12 feet, or a little more, could 
uot be obtained there. 

In my opinion Colonel Abert was justified in rejecting the canal, be¬ 
cause an adequate motive for its construction was wanting; while the 
passes could be improved easily to the depth then demanded. But if 
instead of 12 feet, the question had been of 25 or 2G feet in depth at 
the passes, would Colonel Abert have decided as he did ? I think not. 

11. No breakwater could be constructed in Isle au Breton Pass, in 
the neighborhood of the canal, on account of the damage and deteriora¬ 
tion which might result to the pass itself from the structure; it might 
be placed south of Isle au Breton, but in order to protect vessels 
against storms, from southeast around to northeast, it would be neces¬ 
sary, if there was but one breakwater, to make it in the shape of an L , 
and this form would result in the filling of the interior space with silt, 
and considerable loss of benefit. I think the necessity for a breakwater, 
other than would be afforded bv the construction of the outlet of the 
canal itself, has been much exaggerated. The storms from the south¬ 
east, which are the most violent, prevail exactly at that period of the 
year when the export trade of the Mississippi Valley is at its minimum. 
Against northeast storms, the lee of Isle au Breton, and of the shoals 
around it, would constitute a considerable protection. Large ships in 
that anchorage would ride out any ordinary storm, and it would be 
going too far to suppose that a navigator would allow himself to be 
caught in this cul-de-sac, when he might obtain due notice of the ap¬ 
proach of a hurricane or cyclone. At all events, during the civil war 
our blockaders, composed mostly of merchant-vessels, were able, to 
blockade continuously the ports of the Gulf, and even of the Atlantic 
coast. 

During the prevalence of a hurricane or cyclone the protection afforded 
by a breakwater would not be of the slightest moment; vessels unable 
to enter a port on the approach of such storms have to run out to sea. 


20 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


In a severe gale vessels cannot enter the passes of the Mississippi, Gal¬ 
veston Harbor, nor, I think, any harbor on the Gulf except theTortugas. 

12. It has been said that the board should have included the cost of 

defensive works in their estimate for the canal. The board have 
confined their action to the instructions given them, after a careful con¬ 
sideration of their scope; and, besides, it would have been impossible 
to estimate for defensive works when the location, even, of the canal had 
not been settled. , 

I understand that the defenses at Forts Saint Philip and Jackson 
have been planned under the supposition of t ere being a depth over 
the bar, at the passes, of about 18 feet, and that an increase to 25 feet, 
which is sufficient for the large class of iron clads, would compel a con¬ 
siderable addition to be made to the present projects for those works; 
and further, that the cost of these additions would equal that of any de¬ 
fenses w hich it w ould be necessary to provide for the canal. Supposing 
the passes improved—as they cannot be defended by fortifications—the 
w 7 hole lower part of the river w ould be at the service of an enemy hav¬ 
ing a naval superiority. It is impossible, on the other hand, unless the 
canal be absolutely abandoned to the enemy, for him to make use of it. 
In the question of military defense, therefore, the canal is much supe¬ 
rior. 

13. The minority report appears to differ materially from that of the 
board, but this appearance is due principally to the fact that there are 
two reports discussed in the same paper—the project of Captain Howell, 
and the report of the board—and from a certain inattention to precise 
arrangement the distinction between the two becomes obscure, and the 
reader is apt to mistake which party—Captain Howell, or the board—is 
criticised by the dissenting member. I have analyzed the supposed dif¬ 
ferences and give the result. 

1. The board and the dissenting member consider a canal to be en¬ 
tirely practicable. 

2. Both consider Isle au Breton Pass as suited for the outlet. 

3. Both consider the peninsula of Fort Saint Philip, below the fort, as 
the proper place for the other terminus. 

4. Neither party would consent to place the terminus at a position 
w here the river-bank wns in danger. 

5. Both desire the outlet to be near Sable Point. 

G. Both consider that the canal should be under the protection of de¬ 
fensive works, and of existing ones, if possible. 

7. There are no differences, of wffiich 1 am aware, about the lock. 

8. There w r as no controversy about foundations. 

0. There was no controversy about location, because the board had 
not fixed one. 

10. There is practically no difference about protection to vessels ; and 
probably had there been a complete understanding between the parties, 
of their respective views, this present discussion would not have been 
necessary. 

11. The dissenting member thought the width of the canal-trunk some¬ 
what in excess, but tw o large vessels with a tow-boat on each side would 
take up nearly all the width ; sidings, however, might be constructed for 
passage of vessels. 

12. He, however, objects to the estimate put forward by the board be¬ 
cause no sufficient data for an approximate estimate, even, in his opin¬ 
ion, exist. 

It is proper to say that the board considered the location chosen for 
the project of the engineer in charge as representing the most costly 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 21 


in the amount of work, as well as in the requirements of protection of 
vessels; and adopted it for the above reasons, in order to fix, not an ap¬ 
proximate, but a limiting value of the estimated cost. 

However, when he discusses particulars he makes but one exception, 
viz: that of 50 cents per cubic yard for excavating the trunk of the 
canal, which he considers too little, in view of contingent difficulties; 
from the knowledge which various members had of the cost of dredging, 
the nature of the soil to be excavated from the canal, &c., they were of 
the opinion that 50 cents per cubic yard would be largely in excess, and 
that said excess ought to be ample to insure against probable drawbacks. 

As the minority report considers the character of the soil to be suffi¬ 
ciently known, and even that additional borings to test it are not neces¬ 
sary, the author would have doubtless gratified the board—I can speak 
at least for myself-—by submitting his estimate for a canal, and such an 
attempt on his part would have been entirely feasible, claiming, as he 
does from professional experience, a knowledge of the difficulties to be 
encountered. The board, feeling that differences of opinion might arise 
on the subject of the improvement of the passes, and as the two subjects 
were radically distinct in their nature, decided to make the report on 
the canal separate from the other. Such a course it was thought would 
also have been more conducive to harmony of action. 

Having carefully gone through the work of comparison, I have found 
the supposed differences to have nearly, if not quite, disappeared, and 
am led to the conclusion that, for the canal project, there is not and has 
not been any important difference of opinion. 

With regard to Captain Howell’s project: 

1. The board has not adopted his location, but has left this matter 
subject to results of future examination. 

2. The board has not adopted his mode of constructing jettees. 

3. The board has modified the dimensions and mode of constructing 
the locks. 

4. The board has not adopted the coffer dam and drillage for founda¬ 
tion of lock. 


5. The board has adopted the dimensions of the trunk of the canal. 

G. The board has adopted Isle an Breton Pass for one terminus, 
and the straight reach of the Mississippi below Fort Saint Philip tor 
the other. 

7. The board states the necessity for works of defense. 

The dissenting member thinks that 2 per cent on cost would represent 
the annual expenses of the canal, and this he derives from the Erie 
Canal, but the cases are not parallel, and I consider this percentage 
largely in excess; after the canal is finished and the work consolidated 
I do not see how these expenses could exceed $50,000 per annum. 

1 wish to state that not having been able to consult the other mem¬ 
bers of the board, they are not responsible for the opinions I have 
expressed in this paper, except where I have used the language of the 
report of board. 

Respectfully submitted. 

JOHN NEWTON, 

Lieutenant-Colonel Engineers, Brevet Major-General . 


Brig. Gen. A. A. Humphreys, 

Chief of Engineers, Washington, I). C. 


22 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


United States Engineer Office, 

New York, April 3, 1874. 

r General: I have respectfully to present some observations in review 
of the minority report, dated January 29 last, and offered to furnish 
the views of the dissenting member and the reasons for his non-concur¬ 
rence with the report of the board of engineers, dated January 13,1874, 
upon the subject of the improvement of the passes of the Mississippi. 

STIRRING AND DREDGING THE BAR. 

In 1852 a contract was made with the tow-boat association to deepen 
the Southwest Pass to 18 feet. It is stated that 18 feet was obtained 
in 1853, but it is not stated that the contractors were required to main¬ 
tain this depth after it was once gained. It is stated in the minority 
report that the width of 300 feet was specified in the contract; but was 
it ever obtained? and, if so, where is the evidence? 

The next example is the disbursement of $330,000, appropriated 1>3 T 
Congress, in 185G, for opening and keeping open, by contract, ship-chan¬ 
nels through the bars at the mouths of Southwest Pass and Pass a 
Loutre. Contracts with the Messrs. Craig and Bightor were accord¬ 
ingly entered into for opening both channels to a depth of 20 feet, and 
maintaining that depth four and a half years. After constructing an 
apology for a jettee, the contractors abandoned that mode of operating 
to adopt the system by stirring up, dredging, &c. By these methods 
they succeeded, September, 1858, in opening two channels to a depth of 
18 feet, their contract having been modified that year with respect to 
depth. In the latter part of 1858 those parties refused to comply further 
with their contract to maintain the depth of 18 feet for a period of four 
and a half years. A new contract was entered into with other parties 
for deepening Southwest Pass, but they likewise failed to execute it. 

The remainder of tfie appropriation, $70,000, was then disbursed by 
the officers of the Department, and a depth of 18 feet was maintained 
upon the bar of Southwest Pass for one year. 

In the first example taken the width is doubtful, while the element 
and cost of maintenance of the channel is entirely ignored. 

The second example is deficient by omitting the width ; and the main¬ 
tenance of the channel was not attempted. 

In the third the maintenance of the channel for one year is stated, 
but the width is not. The importance of the omissions noted will be 
perceived by a little reflection upon the nature of the work itself. 

1. The quantity of work will increase directly with the width and 
depth of the cut made in the bed of the channel. 

2. If these dimensions exceed a certain limit the slopes of both sides 
of the channel will slide into the excavation and increase the amount to 
be removed out of all ratio with the dimensions proper of the cut. 

3. When a certain depth and width is obtained the problem of main¬ 
tenance then comes in. Some time is required for the grading of the 
sides due to the new depth, and the maintenance is charged with the 
removal of these land slips, as well as with that of the ordinary deposits 
in the channel. 

4. Again, one season may be extremely favorable for the operations 
of excavating, due to the prevalence of a rapid current, while another, 
owing to the slack currents, may be very unfavorable. 

5. In spite of all regulations the grounding of vessels must occasion¬ 
ally take place, and particularly if the cut is not made of ample width. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 23 


The result of a grounding is the formation of a shoal in the channel-way 
and a loss of depth. 

0. To these must be added filling up the channel excavated, and par¬ 
ticularly the portion near the bar, by the influence of storms. 

The conditions ot the problem as stated above were considered, as r 
well as the results obtained by Captain Howell during his operations 
trom July 1, 1872, to April 1, 1873. At Southwest Pass the records 
show, by reducing mean low water to extreme low water,* that for 
eight days there was a depth of from 12 to 14 feet; for six days, 15 
feet; tor eight days, 154 feet; for eighty-six days, Id feet ; for twenty- 
three days, 16J feet; for twenty-one days, 17 feet; for seventeen days, 
174 feet; for fifty-eight days, 18 feet; and for twenty-three days, 19 
feet. That is to say, one hundred and sixty-nine days when the depth 
was less than 18 feet, to forty-seven days when it was greater than 18 
feet; and it is a fact worthy of note that stoppages of work due to 
slack currents, rough weather, and to fogs, were mainly coincident with 
the prevalence of the lesser depths. These results should he consulted 
in preference to those given in the report of the board of January 13 
last, as they are not only more iu detail, but possess likewise the ad¬ 
vantages of being reduced to extreme low water of the Gulf, which is 
the standard adopted for the ship-canal, and used both in the reports 
of the board and those of the minority. 

The time of two hundred and seventy-four days is accounted for as 
follows: Suspension of work on account of slack current, sixty-eight 
days; fogs, fifteen days; rough weather, fifteen days; repairs, forty- 
three days; Sundays, thirty-nine days; pulling off grounded vessels,, 
four days; coaling, four days; leaving eighty-six days to be credited 
to the work of the machine, as no record exists to state that it was not 
at work. The result is one hundred and eighty-eight days of unavoida¬ 
ble suspension of work, to eighty-six working days. 

The useful effect of the dredgers, measured iu time, would, therefore, 
be only 31 per cent, of its theoretic value, and this result, taken from the 
records of the most improved machinery, constructed and worked under 
the eyes of engineer officers, if considered in relation to the fact before 
shown, that the amount of work under varying depths and widths of 
excavation may differ vastly from their numerical ratio to each other, 
shows conclusively that there is a practical limit of improvement by 
this process, which is suddenly reached. 

The official records thus analyzed would not warrant the board in es¬ 
timating a greater depth than 18 feet at extreme low-water as capable 
of being maintained at the passes by means of the stirring process ; and 
there would seem to have been some reason for all former trials having 
been arrested when the depth of 18 feet, or about that depth, was ob¬ 
tained, as if the real difficulties of the case had then begun to be encoun¬ 
tered. However that may be, these significant coincidences do exist. 

It should have been stated in the report of the board of January 13 
last that the depths obtained by Captain Howell at Southwest Pass are 
referred, not to extreme low water, but to mean low water, while the 
depths obtained at Pass a Loutre from April 1 to June 30 are errone¬ 
ously referred to “extreme low water,” instead of to mean low water. 
This correction of the depth obtained at Pass a Loutre would reduce it 
from 174 feet to about 10J feet. With nothing practical to rely upon 

* This is not strictly correct. Extreme low water as observed in 1851-52, Appendix 
A, Humphreys and Abbot, is lower by nearly 3 inches than the standard here assumed 
for purposes of reduction. 




24 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


save the records of the trials of 1853, 1858, and 1859, which are defi¬ 
cient in essential elements, and consequently useless for scientific inves¬ 
tigation, the minority report does not hesitate to lecture the board in 
this wise: 

In face of these facts, in face of the positive, formal, and official statement of the 
engineer in charge, that so far as regards obtaining a 20-foot channel the natural ob¬ 
stacles have been overcome, (reiterated under different forms,) and in face of the fact 
that since the proved success of stirring up by scraping with harrows, &c., for $60,000 
a year, machinery expressly designed to this end has been invented and improved 
upou, under the eye of engineer officers, to be operated at an expense of $200,000 per 
annum, the majority of the board advise you that “ the results so far do not warrant the 
board in estimating a greater depth than 18 feet at extreme low water, as capable of 
being maintained at the passes by means of the stirring-up process and, furthermore, 
that this is inadequate to the requirements of the naval, military, and commercial 
services. 

Let it bo noted, first, that the engineer in charge does not state that 
he maintained, but only obtained, 20 feet of depth, and that depth was 
at mean, not at extreme low water. 

The necessity for this forcible if not courteous arraignment of the 
board by one of its members might have been spared if some space had 
been devoted in the minority report to the recorded results of that 
“machinery expressly designed” * * * * “invented and improved 

upon, under the eye of engineer officers,” and “ operated at an expense 
of $200,000 per annum.” Now, although the records of the actual work 
of that machine at Southwest Pass had been collated by the board 
and published in their report, the minority report has not been tempted 
even to allude to them, far less discuss them. 

Why the records of a past time so imperfect as to admit of any and 
every deduction have been relied upon to the exclusion of the full and 
precise information which could have been found in Captain Howell’s 
last report upon the stirring process, is not in my power to explain. 

One great objection to the moderate depth over the bar, which the 
dredgers are capable of yielding, is the fact that in rough weather it 
could not, on account of the swell, be availed of by vessels drawing the 
full, or nearly full, draught which the bar afforded, and at the very mo¬ 
ment when an entrance is most needed. It is important likewise to 
remember that one effect of storms would be to create an actual obstruc¬ 
tion at the bar by washing sand into the entrance. 

It seems evident, from the above considerations, that, in order to make 
the navigation of the passes safe as well as convenient to commerce, 
something more than the bare draught of vessels must be considered in 
establishing the depth over the bar. 

After the elaborate discussion of the benefits of the stirring process, 
and the conclusion that “ with 20 feet at extreme low tide, (which is as¬ 
sumed to be maintained,) “vessels drawing 22 j feet could, owing to the ' 
softness of the bar, frequent the port of New Orleans, and for mere 
commercial purposes probably 20 feet draught would be adequate; a 
draught of 23 feet will include 85 per cent, of the shipping of the world; 
and with a draught of but 18 feet vessels (steamers) can be built of 5,000 
tons carrying 70,000 bushels of corn, or about 11,000 bales of cotton,” 

I felt prepared to consider this as the settlement of the question on the 
part of the minority report, as well against the jettee-system, which it 
advocates, as against the canal, which it reprobates. lint no ; however 
potent the argument may be against the latter, “still,” (to use the 
words of that report,) “ an improvement of one or more of the natural 
mouths by which a sufficient depth should be afforded without the con¬ 
tinuous use of machinery * * would be desirable.” As to defensive 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


25 


measures to protect the dredgers in time of war, none could be taken, 
unless vessels of war were detailed to this end; otherwise, without the 
necessity ot a blockade, they would be at the mercy of every cruiser of 
the enemy which might choose to make a dash at them. Practically, 
therefore, dredging could not be carried on during a period of hostili¬ 
ties. 

I feel no sympathy with the efforts made to demonstrate that the val¬ 
ley of the Mississippi would be sufficiently accommodated with a depth 
of entrance to its great river, so inferior to those of the principal ports 
of the country, believing that such depths will rule the draught of ves¬ 
sels frequenting our ports, and that a deficiency in that respect would 
make an unfortunate discrimination against the commercial prosperity 
of any locality. 

Baltimore has felt this, and is now dredging to obtain a 24 foot chan¬ 
nel leading to its port. I have from the first maintained that, leaving 
naval uses out of consideration, the necessities of commerce alone 
demand a depth of at least 24 feet at low water for an outlet to the Mis¬ 
sissippi, an l nothing short of this will ever fulfill the conditions of the 
problem. The importance of making the Mississippi accessible to the 
larger classes of naval vessesl cannot be overrated. It not only “ fur¬ 
nishes a harbor of several hundred miles in length for vessels of any 
attainable dimensions and draught, but it furnishes in unlimited quanti¬ 
ties, and at the lowest prices, all that is needed in ship building, whether 
in wood or iron, and for the outfit of fieets and armies. To make the 
Mississippi, therefore, accessible to vessels, of war, is to do away with 
the need of other inefficient naval depots, such as that at Pensacola, 
and to furnish centrally to the northern coasts of the Gulf the much 
needed depot and arsenal for naval operations.” 

The above, extracted from a paper submitted by Colonel Barnard, 
expresses forcibly the other (beside commercial) advantages which 
would be conferred by a liberal policy of improvement in this quarter. 

A depth of outlet about 25 feet at extreme low water would suffice to 
convert the Mississippi into such u depot and arsenal for naval opera¬ 
tions,” and I cannot, in view of the object which the resolution of Con¬ 
gress imposed upon the ship-canal, viz, to be suited for military, naval, 
and commercial purposes, agree to have an improvement of the passes 
(to take the place of the canal) discussed upon the idea of obtaining 
merely IS, 19, or 20 feet, a depth manifestly incapable of meeting the 
wants of the Navy. 

The board discussed the canal-project and the jettee system under the 
restrictions of the above resolution, and no discussion which ignores 
these can be considered to be either a review or reply. 


IMPROVEMENT OF TIIE PASSES BY MEANS OF JETTEES. 

The board of 1852 recommended, in the event of not obtaining suffi¬ 
cient depth by means of the stirring process at Southwest Pass, to re¬ 
sort to the system of jettees. Among those who signed that report was 
the memberVho has constituted the minority in this board. In a com¬ 
munication dated December fi, 1873, which has passed through the 
hands of the Chief of Engineers, he presents his views upon the im¬ 
provement of the passes, lie adopts Pass a Loutre as more favorable 
than Southwest Pass, apparently for two reasons : 

1. A shorter distance from the interior depth of 25 feet to the outer 
crest of the bar. 

2. A smaller annual advauce of the bar into the Gulf. 


26 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


As that paper lias had an important share in shaping the form which 
the discussion of the improvement of the passes has since assumed, a 
brief synopsis of its plan of application of the jettee-system to Pass a 
Loutre will be useful: 

1. The distance of the interior depth of 25 feet at low water from 
the outer crest of the bar was assumed to be two and a half miles. 

2. The natural width of the channel when that depth obtains was as¬ 
sumed to be one-half mile. 

“ 3. Parallel jettees starting from the cessation of 25 feet depth,” (above 
the North Pass,) “ closing this pass, extend a half-mile apart, four miles 
to points opposite the outer crest of the bar, in about 10 feet water. 

“4. Perfect parallelism is not necessary. Large deviations may be 
made to select the best location. 

“ 5. Now, of the four miles on each side of jetteeing and leveeing com 
biued, (for a large proportion of it should lie called levee,) 
two-thirds, perhaps three-fourths, may be laid on the ground bare at low 
water, or permanently out of water. Of the remaining one-eighth or one- 
fourth, scarce any of it is in depth greater than 10 feet. 

“ G. The average cross-section of jettees and levees is assumed to be 
15 feet wide and 10 feet deep. 

“ 7. The effects of these embankments is described as follows: The 
25-foot channel will be extended at once two and one-half miles * * 

the bar must be excavated to 25 feet. The velocity of current main¬ 
tained unimpaired up to this point will carry its sediment far beyond 
into deep water. The present regime of a shoal-bed cannot again be 
restored until the vast bottom area, now covered with deep water be¬ 
yond, for a distance of two and one-half miles, is raised. 

“8. The jettees being once extended out to the crest of the existing 
bar, they do not require the incessant following up supposed$ though 
that they may ultimately require extension, I do not dispute. 

“ 0. I estimate that Pass a Loutre has advanced in twenty-nine years 
something over 200 feet per annum, say 225 feet. There seems no good 
reason for the assumption that the advance will be more rapid than can 
be easily dealt with, nor that continued and incessant work will be 
required. 

“The very first operation is an advance of the deep channel two and 
a half miles, just twice as much as the bar has advanced in twenty-nine 
years. 

“I feel that I am justified in recommending it (the jettee-system) as 
probably furnishing the most speedy attainment of a deep-water channel, 
and one which will have some feautures of permanence ; * * 

and then illustrating the example of the Sulina mouth of the Danube. 

“Indeed, the effect of the jettees has been the diminishing by more 
than one-half the old rate of the advance of the delta at the Sulina 
mouth as represented by the 24-foot line and 30-foot line of soundings, 
and this Sir Charles Hartley considers to be due to the circumstances 
that the great bulk of the silt-bearing waters of the river, on issuing, as 
at present, at once into deep water beyond the pier-heads , is, as a rule, 
carried far to the southeast by the littoral current, instead of flowing 
into the sea, as formerly, with a feeble and constantly-decreasing current, 
by numerous shallow channels, &c., and it was also found that the action 
of the sea on the bottom, during storms, swept away the banks depos¬ 
ited beyond the north pier-head. 

“A 4 littoral current’ may not exist at the passes, but the efficient action 
of waves and currents produced by storms may be reasonably counted 
upon to retard, as they always have done, the rapid advance of the sed- 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 27 


imental deposite , which, as at the Sulina, projected with undiminished ve¬ 
locity into the deep waters beyond the bar-crests, (at present the velocity 
has been nearly destroyed when the crest is reached,) will be dissemi¬ 
nated far and wide.” 


These extracts offer a definite project for our consideration, and its 
author states, in express terms, the results to be expected from its con¬ 
struction. 

1. Although he accepts a width of river between banks of one-half a 
mile, as corresponding* to the depth required, 25 feet at extreme low wa¬ 
ter, yet he advocates large deviations in excess of this width, in order 
to secure the best location for his jettees, and obtains by this novel, if 
not correct, mode of treating parallel jettees, the opportunity of making 
a presentation of his system sufficiently favorable in point of cost. 

2. Notwithstanding his statement that the depth of 25 feet ceased to 
obtain above the division or fork of the pass, yet, in another and sub¬ 
sequent communication, he perceives no necessity of closing oue of the 
outlets in order to obtain in the other the depth desired. 

3. The result of such jettees, he asserts, would be not only to push 
forward the depth of twenty-five feet to the bar, but also to prevent the 
formation of a shoal depth over it until the deep space ahead in the 
Gulf, for a distance of two and a half miles, should first be filled. After¬ 
ward, to furnish some idea of the time required to accomplish this, he 
states the distance to be tilled corresponds to the progress of the bar for 
fifty-eight years. 

4. It is not suprising, after the above, that he concludes the incessant 
following up of the bar, by extension of the jettees, to be superflous, 
though he will not deny that ultimately they may require extension. 

5. He appears to rely upon the precedent of the successful issue of 
the jettee-system at the Sulina mouth of the Danube as a guarantee for 
the application of the same method to the mouths of the Mississippi. 
But Colonel Stokes, of the royal engineers, and Sir Charles Hartley, 
the engineer of that improvement, both of whom were connected with 
it from commencement to completion, in their speeches and writings, 
concur in attributing whatever permanence may attach to the improve¬ 
ment to the existence of a littoral current tending to the southward; 
which, aided by the northeast storms, breaking and stirring up the 
shoals, transports the matters suspended in the river waters, as well as 
that portion deposited upon the bottom, away from the outlet of the 
jettees. 

This action has hitherto prevented the growth of the bar, and will 
preserve it in statu quo until the gradual advance of the deposites from 
the other mouths of the Danube shall have forced out the littoral cur¬ 
rent from the end of the jettees, in which event the latter will have to 
be extended. 


In his first paper, the advocate of the jettee-system for the Missis¬ 
sippi mouths relies upon the action of the waves alone to break up and 
transport away from the outlet the large mass of deposites , apparently 
forgetful of the influence of the waves to form the bar, and that any 
channel through it is due solely to the river currents. In all cases, 
whether a current flows or still water obtains between the jettees, un¬ 
less the ends of the jettees are founded at such depths that waves can¬ 
not act upon the bottom, supposed to be composed ot movable mate¬ 
rial, the tendency of storms is to develop a shoaling. 

In a second paper, by the same author, apparently aroused to the 
important part which it did have in the improvement of the Danube, 
he asserts that there is a littoral current off the mouths of the Missis- 


28 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


sippi, and refers for proof of its velocity to page 449 of u Physics and 
Hydraulics of the Mississippi.” 

It was impossible to have made a reference more out of place. The 
subjects treated therein are the ebb and flood tides and the tidal veloci¬ 
ties in mid river , but nothing concerning littoral currents. 

But the minority report might have referred to a report by Mr. (since 
Major-General) G. G. Meade, of a survey made by him in 1838, of South¬ 
west and South Passes, and to be found in the work above named, in 
which, after careful observations conducted from the bar to a distance 
of seven miles outside, he states that he failed to discover the existence 
of any littoral current. 

Analogy, therefore, between the Danube and the Mississippi, as to 
the element of a littoral current , which was declared so important to its 
improvement, by the engineers engaged at the former river, falls to the 
ground. In subsequent portions of this paper I will show that, except 
the bare fact of both being delta rivers, similarity does not exist be¬ 
tween the Danube and the Mississippi. 

I shall not in this discussion ignore or reject the facts and conclusions 
of the survey made by order of the Government, and reported in u Phy¬ 
sics and Hydraulics of the Missisippi.” This work, elaborate in detail, 
and remarkable for the clear light which its admirable handling of spe¬ 
cific facts sheds upon the physical laws governing the river, cannot be 
passed over to receive, in lieu thereof, inconclusive examples taken from 
foreign rivers. 

The published information concerning the Danube, and bearing upon 
the points in discussion, does not at all compare in scope and scientific 
value with the exhaustive treatise which we possess upon the Missis¬ 
sippi and its delta. Our engineers, then, can obtain vastly more in¬ 
formation from sources in their reach concerning our great river than 
all the published information available can furnish of the Danube or 
other foreign river. 

The board, in their report of January 13 last, in imitation of the pro¬ 
ject already extracted from the minority paper of December 0 last, and 
with the view of submitting its conclusions to a test, adopted the sys¬ 
tem of parallel jettees for the deepening of the bar at Pass a Loutre. 
After a careful examination of a chart upon a large scale, compiled from 
recent surveys, the distance apart of the jettees was assumed to be 2,200 
feet, that width corresponding to the width of the pass where the depth 
of 25 feet was obtained. 

The jettees were held strictly to that distance apart, in order that the 
complete effect of parallel jettees upon the bar might be obtained. 

In what follows I will adhere to the principles and conclusions con¬ 
tained in the report of the board, although taking the liberty to discuss 
the subject in my own way. « 

1. Assuming that the width of 2,200 feet would suffice to maintain 
a channel of the required depth in the pass, it would not carry it to 
the bar, for these reasons : At the bar the wave-action would tend di¬ 
rectly to decrease the depth; the intrusion of salt-water at certain 
periods within the jettee-heads would interfere with the normal condi¬ 
tions of scour; the loss of velocity due to great lengths of jettees would 
exercise an unfavorable influence; and, finally, the recurrence of periods 
of medium velocities without floods would cause greater deposits upon 
the bar. The Sulina mouth is a case where it has been attributed to 
the last-named cause that the navigable depth varied, at periods from 
1862 to 1869, between 174 and 134 feet. Hence the distance between 
the jettees must be decreased as the bar is approached. 


IMPROVEMENT OE MOUTH OF THE MISSISSIPPI RIVER. 29 


2. When the jettees shall have arrived at the position of the original 
outer crest of the bar, it will be found, thanks to the ordinary as well 
as to the extraordinary advance of the bar, due to the construction of 
the jettees, that the outer crest has been pushed ahead about 1,800 feet 
into the Gulf. An ordinary advance of 302 feet per annum, and a mod¬ 
erate period of three years for the construction of about eight miles of 
jettees, are here supposed. 

Owing to the slope at which the bar will advance into the Gulf, the 
depth on new outer crest will have decreased between 3 and 4 feet, and 
hence, in order to maintain the depth of 25 feet, the jettees must be 
pushed out until the new crest is attained. 

Upon the Rhone, when the jettees were completed, in 1852, the bar 
was about seven eighths of a mile in advance; in 1803 this advance 
was nearly one and three-fourths miles; the progress during this inter¬ 
val having been three times the ordinary rate. 

The depth on the bar was always much less than that between the 
jettee heads, and any partial variation of depth over the bar seemed 
due to freshets in the river. A littoral current is found of one and one- 
tenth to one and five-tenths miles per hour. The matter held in sus¬ 
pension and discharged is stated to have been 583,GG6,0GG cubic feet, 
equivalent to 30,480,000 tons per annum, of which 137,333,333 cubic 
feet, or 8,583,333 tons, were carried off by the littoral current. 

As a comparison, the littoral current at the Sulina mouth is from 
seven-twelfths to one and one-sixteenth miles per hour, and the amount 
of matter yearly discharged through this mouth is about 2,510,000 tons. 

The amounts discharged through certain passes of the Mississippi are 
as follows: Southwest Pass, 67,130,000 tons per annum ; Pass a Loutre, 
45,975,000 tons per annum ; South Pass, 15,810,000 tons per annum. 

Although the piers at the Rhone were not carried out to the bar , their 
results have been valuable in demonstrating that the effect of jettees, 
by concentrating a current upon the bar, would be to increase greatly 
its rate of advance, while their action upon the depth on the bar was of 
little benefit, and that was confined to times of freshets. 

This example is likewise a complete answer to the argument of the 
minority report, that the jettees, if carried to the outer crest of the bar, 
would not require continual extension, for the cause therein assigned, 
that a shoal bar could not again be found until the deep space ahead, 
for a distance of two and a half miles, should first have been filled. 

The disappointment suffered from the application of the jettee sys¬ 
tem led to the construction of a lateral canal connecting the Rhone 
with the Gulf of Foz, and having a depth of 23 feet. 

3. Let it be supposed, that the jettees, following up the bar, have 
finally reached its outer crest. Owing to the meeting of the river waters 
with those of the Gulf, the former will be deflected upward at an an¬ 
gle, a result which is apparent even from considering the lateral spread 
of these waters after having been released from the confinement of the 
jettees, and their decrease in depth consequent upon an increase in 
width. 

Now, it is obvious that the materials rolled by the currents upon the 
bottom will be arrested as soon as they reach this dead angle, or space 
without currents, and that the upper surface of the new bar will be 
coincident with the slope at which the river waters incline upward. If 
this first formation be supposed to take place during a river flood, the 
bar will progress until the period of slack currents, at which time the 
deposits will be upon the slope already formed and at its foot. AN hen 
the next flood comes the waters will be deflected by the slope first 


30 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


formed, and the material first deposited upon the slope and at its tool 
will be carried forward until they reach the new crest, when they will 
be dropped over to form the exterior slope of the bar. In this mode the 
bar is formed and continued, and it is evident that as the crest ot the 
slope rises continually in height as it recedes from the jettees, so these 
must be extended to keep it down, and preserve the proper depth lor 
navigation. 

The matters held in suspension by the river waters are mainly carried 
forward by the currents into the Gulf, where they are deposited, and 
serve to raise the level of the bottom, but the bar proper is composed 
of materials rolled upon the bottom and arranged in the forms and by 
the influences already described. The matters carried in suspension by 
their deposit simply prepare a foundation for the bar, which is after¬ 
ward regularly constructed upon its surface. 

This distinction, which is so clearly made in the u Physics and Hy¬ 
draulics of the Mississippi,” has been little attended to by writers on 
the subject, and the neglect of it has led to many errors and false 
notions. 

From the view which has been presented of the agencies at work, 
which are incessantly tending to diminish the depth, the necessity ot 
converging the jettees, and of so placing and constructing them as to 
coerce and control the currents, becomes manifest. These jettees soon 
cease to be mere margins to the channel, or to act simply as banks to 
a river; on the contrary, they must be brought into close contact with 
the currents as well as waves, to resist not only their action, but like¬ 
wise to compel the currents to perform their necessary work. 

The jettees, among other casualties, are exposed to be frequently un¬ 
dermined, and must therefore be founded deep enough to be out of 
reach of such contingency. 

It is not necessary to enlarge; this brief sketch is sufficient to suggest 
to the engineer the cost as well as difficulties, not merely of commencing 
a system of jettees upon a foundation proverbial for want of tenacity 
and resistance, but of prosecuting it to a successful completion, and of 
making large annual extensions into the Gulf, in the face of the severe 
storms of the locality. 

4. The second minority report, of January 29th last, in dealing with 
the example proposed by "the board, of parallel jettees 2,200 feet apart, 
which was intended to imitate the system recommended in the first 
minority report, does not do justice to the report of the board. That 
report demonstrated that as the bar is approached the jettees must be 
brought closer than the width in the pass corresponding to the depth of 
25 feet. In other words, that if this width on starting be 2,200 feet it 
must be decreased as the jettees are extended. 

The decrease of width would bring them into deeper water, and 
therefore make them more costly. But the board did not consider this 
unfavorable feature of the case in judging of the cost, but treated them 
as parallel and at the same distance apart as at the start. This cer¬ 
tainly was not u elaborately unfavorable” to the jettee system; and if 
the jettees for the whole or any part of their length did lie in deep water, 
that must be attributed to the starting width between them. 

It is obvious this is correct, and, unless in very peculiar local circum¬ 
stances, the engineer would be in error who should increase such width; 
but we have seen, on the contrary, that he must decrease it as the jettees 
lengthen. The author, however, states the board is u erroneous in prin¬ 
ciple”—for what, in view of this statement, I cannot divine—and even 
cites the work on u Physics and Hydraulics of the Mississippi,” as well 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 31 


as the improvement of the Sulina month of the Danube, to prove his 
position. I have looked carefully over these citations and find that 
they do not answer the purposes lie intended. The question is simply 
whether if 2,200 or any other number of feet corresponds to the width 
of a river having a depth of 25 feet, an increase of that width will not 
lessen the depth. The board may say what it will, and the minority 
report says, if there is meaning attached to its words, it would not. 
Such questions cannot be argued. 

5. It is evident that in proportion as the cross-section of discharge 
on the outer crest of the deposit or bar widens, its progress into the 
Gulf will become slower, and, on the other hand, if the cross-section be 
narrowed, the progress of the deposits will become more rapid; whether 
the relative progress be in the simple inverse ratio of the widths of dis¬ 
charge or in some other, it is not important here to inquire. The essen¬ 
tial fact, that as the width of the cross-section diminishes, the rate of 
progress of the bar into the Gulf must increase, is self-evident. 

Let us test by this rule the relative advances of the bars at the mouths 
of the Southwest Pass and South Passes and of Pass a Loutre, each 
mouth being supposed to be treated with the jettee system, and the 
width of cross-section at the end of the jettees being that corresponding 
to the maintenance of the depths of 25 feet on the passes themselves. 



Southwest 

Pass. 

Pass Loutre. 

South Pass. 

X itural width of cross-section of discharge iuto the Gulf miles. 

Width between heads of jettees.do.. 

Ratio between these...<lo.. 

Present annual rate of progress of the bar.feet 

Estimated annual rate of progress of the bars after completion 
of jettees.feet. 

21 

% 

3 

33+ 

1,014 

If 

42100 

4 

302 

1, 208 

1 

1 

8 

8 

280 

2, 240 


The widths of all these bars have been taken from the Coast Survey 
map, and upon the same principle of measurements; on account of the 
smallness of the scale, the dimensions taken are not assumed to be 
strictly accurate. The width between jettee-heads at Pass a Loutre has 
been assumed to be 2,200 feet; though at this pass, on account of the 
abnormal state of things produced by its two mouths, this width apart 
for the jettees is not so certainly correct as at Southwest Pass and at 
South Pass. While the estimated annual advance of the bar at South¬ 
west Pass and at Pass a Loutre may be said to be, and probably will be 
the same, that for the South Pass is much greater than either. 

I do not rely upon this method to furnish accurately the absolute, but 
it is evidently an approximation to the relative, advances of the bars, to 
which exception cannot justly be taken, and places the Southwest Pass, 
therefore, in an unfavorable light for improvement by jettees. 

Sir Charles Hartley has said, and in this he has been cited repeatedly 
by the minority reports, that an outlet having a large discharge was at 
a disadvantage for improvement with another having less discharge, on 
account of furnishing more material for the formation of the bar, and 
because the bar was usually further out. This is correct as far as it 
goes, and it may be true, owing to the littoral current and other pecu¬ 
liarities, for the Danube, to which he particularly applied the principle. 
But its application to all rivers would lead to grave errors, because 
another general principle has not been considered, viz, the increased 
progress forward of a bar due to increased width of discharge. 

The effect of the application of the last rule upon the relative advan- 
















32 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


tages of the Southwest Pass, Pass a Loutre, and South Pass has been 
to change the aspect of matters as to the choice of the passes tor a per¬ 
manent improvement. The discharge through the Southwest Pass is 
T 3 0 4 (T ; through Pass a Loutre, iVolS and through South Pass, only Tu 8 ( j6 
ot‘ the whole discharge of the Mississippi, and yet, cut and carve as 
you will the figures in the table above, the annual progress of South 
Bar, after the application of jettees, will not be reduced lower than 1J 


that of Southwest Bar. 

fi. An examination of the longitudinal section of the bars will lead to 
deductions of practical value. 

The slopes of the bars interior to the crest give for each depth of wa¬ 
ter the inclination at which the erosive effect of the currents at that 
depth, and the material of which the bar is composed, hold each other 
in equilibrium. For Southwest Pass, at a depth of 25 feet, this incli¬ 
nation or rise is a little more than 1 foot per 1,000 ; for Pass a Loutre 
the inclination is 1 T 8 0 feet per 1,000 ; and for South Pass at least 2J feet. 
The slopes of the bar at this pass are very irregular, in strong contrast 
with the other sections, and seem to indicate intermittent instead of the 
regular and constant action of the currents prevailing on the other bars. 

The growth of the new bar beyond the jettee-heads will not be at a 
less inclination than those above given. Taking, then, the annual ad¬ 
vance of Southwest Bar under the action of jettees at 1,000 feet; of 
Pass a Loutre, 1,200 feet; and South Bar at only 1,500 feet, and the 
diminutions of depths in one year will be respectively 1 foot, 2.10 feet, 
and 3f feet, and hence the necessity for annual extensions of the jettees 
will be more urgent at South Bar than at any other. . 

A similar relation of slope in the bars will be found by considering 
the flare* of the mouths of the passes. This element would approxi¬ 
mate to the real flare or spread of river-waters as they emerge from the 
jettee-heads, and give us the means of calculating that slope. It is not 
assumed that the results given in these methods of obtaining the rise 
of the bar as it advances into the Gulf are absolutely correct, the scale 
of the maps available for use being too reduced for that, even if the 
methods themselves were mathematically correct, which isnot pretended 
to be said. But the results thus furnished will show the approximate 
relation between the bars in respect to their rise as they advance, and 
thus enable us to discriminate for or against a certain pass. The three 
passes having thus been relatively tested as to capacity and eligibility 
for improvement by jettees, the following results are obtained : 

Southwest Pass is the most advantageous, except in the first outlay 
for jettees, these being about nine miles altogether in length; the ad¬ 
vance and vertical rise of the bar-formation are less than in any other ; 
the width between jettees of 3,900 feet, corresponding to the depth of 25 
feet, gives it great advantages for permanence, as the necessity for con¬ 
verging these will not, as soon as in the other passes, create such 
obstruction to discharge, that the flowing waters will abandon it for 
another pass. 

Pass a Loutre: the jettees here would not differ materially in length 
from the preceding example, and the pass is rapidly approximating to 
Southwest Pass in eligibility; but at present the abnormal state of 
things arising from its bifurcation and the concavity of one of the jet¬ 
tees toward the currents render it far inferior to the latter. 

As to South Pass, the length of both jettees would be about four and 
two third miles, but the extension and vertical rise of the bar-formation 


*At the width of 


Pass corresponding to 25 feet in depth. 





IMPROVEMENT OF MOUTH OF TIIE MISSISSIPPI RIVER. 33 


would be much greater than in the other cases. Its narrow width, be¬ 
tween jettees of only GGO feet, would soon be consumed by the conver¬ 
gence necessary to keep up the scour. 

The longitudinal section of its bar and bed, by its irregularities, indi¬ 
cates very clearly that the shoaling process is going on throughout, and 
that the pass at the present time is hanging between the conditions of 
a live pass and a stagnant ditch ; to the last of which results it must 
arrive, if a revolution in the delta does not redeem it. And this most 
probable fate will be precipitated by applying the jettee-system to its 
mouth. The shoal at the head of this pass is permanent, and results 
from the manner of discharge of the main trunk of the river. The 
application of works constructed to dissipate this bar would, in such a 
situation, be precarious, even if at all practicable. Some relief, however, 
may be possible by dredging or stirring. 

The prominent physical features of the Danube are quite different 
from those of the Mississippi, and it is proper, in concluding this paper, 
to briefly glance at them. This river separates into two branches at Is¬ 
mail Chatal, viz, theKilia and the Toulcha; and the latter, after eleven 
miles, into two others, the Saint George and Sulina branches. 

The distances to the sea from Ismail by the Kilia is ninety-six miles; 
by the Sulina, seventy-eight miles; and by the Saint George branch, 
ninety miles. The triangle thus formed, having Ismail as its apex, has a 
base of forty miles along the sea-coast, and a perpendicular of fifty-eight 
miles. 

The first difference between the Danube and Mississippi is, that the 
former has divided into three long branches, each of which is an active 
stream, whereas the Mississippi has no branches, but pushes its trunk 
undivided to the Gulf. 

At Isatktcha, fifteen miles above the division, the Danube is 50 feet 
deep and 1,700 feet wide. At Fort Saint Philip, twenty miles above the 
head of the passes, the depth of the Mississippi is 151 and its width 
2,360 feet. Its great depth constitutes another point of difference, which 
the Mississippi also maintains in its passes. 

The average specific gravity of the matter held in suspension in the 
Danube is 2.5 ; that of the banks 2.7; and for the Mississippi the latter 
element is 1.9G. The specific gravity of materials on Southwest Bar, 
after it had been sifted from finer materials by the action of currents 
and waves, was 2.G, or about the same as that of the suspended matter 
in the Danube. 

The proportion of silica in the material brought down by the latter 
river is very large—about G7 per cent. 

It is not surprising, if we read, that at the Sulina mouth large ware¬ 
houses have been erected on the banks alone as a foundation; that a 


crib 30 by 15 feet sunk off Sulina mouth, and loaded with 130 tons of 
stone, remained for nearly one week supported on only ten square yards 
of foundation, without the least settlement, and that the driving of a 
single pile 13 inches square in the line of piers to a depth of 1G feet was 
a day’s work for one driver. 

Dunes of sand, 30 to 40 feet, are encountered at the Kilia mouths, and 
of smaller dimensions at those of the Saint George. 

What a contrast the above otters to the mud-shoals and banks of the 
mouths of the Mississippi, in which it is said that the weight of a man 
will send a pole down to a depth of 9 feet. Upon the surface of the 
bar, where the waves and currents sift out the finer materials, there is 
of course a deposit of more or less sand. From this brief analysis of 
H. Ex. 220- 


-3 



34 IMPROVEMENT OF MOUTH OF TIIE MISSISSIPPI RIVER. 

physical differences between the two rivers some important deductions 
may be made. The strength and resistance of its banks is the cause, 
probably, why, having once separated into three branches, the Danube 
has been unable to reform its main trunk, or that the cross-section ot 
either branch has not become so great as to convert the others into 
mere drains for overflow. 

In the Mississippi, owing to the nature of its sedimentary deposits, 
the main trunk cannot be divided, because it has the power always to 
excavate its bed to the depth and width required to carry off its waters. 
N T o crevasse or artificial outlet has ever yet formed a branch to this river. 

The same reasoning applies to the passes, which, perforated through 
the most yielding alluvions, will always suffice to discharge the river, 
and should one by some obstruction be impeded in its discharge, the 
others enlarge their cross-sections to supply the emergency. 

It is this freedom to discharge under all circumstances which makes 
it a delicate operation to obstruct the flow of water through any one of 
the passes, under the plea of improving the navigation. The rapid ex¬ 
tension of a pass by jettees, though under all circumstances prejudicial 
to the discharge through it, would not be so soon felt in its consequences 
in the ordinary river; but at the Mississippi delta, such an operation 
might inure to the rapid deterioration or ruin of the pass, and this is 
the reason why the application of the jettee system to these mouths 
must sooner or later wear them out by forcing the waters into other 
channels. I send here sketches of the Balize bayou, which was the 
main entrance to the river at the first settlement of the country. These 
sketches are of 1722, 1724, and 1731. During this interval the pass 
shrunk in width to the comparative dimensions of a ditch. The ra¬ 
pidity of the change is the striking feature which could not have oc¬ 
curred except in the soil and the other conditions of the Mississippi 
passes. 

The first indication of the change appeared to have been that the 
outer bar became deep, while the shoal lodged in the pass itself, and 
its juncture with the Southeast Pass. 

There are no recognized relics of the delta forms, which have in for¬ 
mer years occupied successively various positions in the lower portion 
of the Mississippi. Delta after delta has disappeared, and the question 
is, how does the trunk, after a certain elongation of the passes, impatient 
at the obstruction which their lengths offer to a free discharge of its 
waters, break through into the Gulf and commence a new formation ? 
Such a revolution, impossible where the river empties into a shoal sea, 
is by no means so when the depth is great. On the other hand, after a 
certain elongation of the passes, do all the parts move gradually into 
the Gulf, the head of the passes and trunk, like the brush of a broom 
at the end of its staff, without breaking their connection 1 I am aware 
these questions cannot be answered, except that the delta was once at 
INew Orleans, and is now in its present location. The present age of 
the delta is at least three hundred years, and the passes are rather 
long, and if the movement is not gradual, it must suddenly come. No 
observations, so far as I am aware, have been made with the view ol 
noting any movement. 

This is not mere speculation, though it may have that aspect; there 
is nevertheless a practical side to it. The outlets of the passes are mov¬ 
ing at the average rate of 2G2 feet per annum, and the whole delta must 
in a certain period of years correspond to the same movement either 
gradually or by a sudden burst. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 35 


Either view would have an important bearing upon the improvement 
ol the passes by the means of lixed artificial works. 

Ee spectfu 11 y submitted. 

JOHN NEWTON, 

Lieut. Colonel Engineers , Bet. Maj.-Gcn. 

Brig.-Gen. A. A. Humphreys, 

Chief of Engineers, Wash ington , 1). C. 


[House Ex. Doc. No. 113, 43d Congress, 1st session.] 

CANAL CONNECTING THE MISSISSIPPI RIVER WITH THE GULF OF MEXICO. 

Letter from the Secretary of War , in answer to a resolution of the House , of 
March 14, 1871, in relation to a ship-canal to connect the Mississippi 
River with the Gulf of Mexico. 

War Department, February 4, 1874. 

The Secretary of War has the honor to transmit to the House of 
Eepresentatives, in compliance with resolution of March 14, 1871, a 
letter of the Chief of Engineers of the 4th instant, submitting reports 
of the board of engineers and of Oapt. C. W. Howell relative to a ship- 
canal to connect the Mississippi Eiver with the Gulf of Mexico. 

WM. W. BELKNAP, 

Secretary of War. 


Office of the Chief of Engineers, 

Washington , 1). (7., February 4, 1874. 

Sir : In compliance with the following resolution of the House of 
Eepresentatives, dated March 14,1871, “that the Secretary of War be, 
and he is hereby, requested to cause an examination and survey, with 
plans and estimates of cost, to be made by an officer of engineers, for a 
ship-canal to connect the Mississippi Eiver with the Gulf of Mexico, or 
the uavigiable waters thereof, of suitable location and dimensions for 
military, naval, and commercial purposes, and i that he report upon the 
feasibility of the same to the House of Eepresentatives,’ 7 Oapt. C. W. 
Howell, Corps of Engineers, was, with your sanction, assigned to the 
duty of making the survey referred to. Having- completed this duty 
and submitted his report, it was deemed advisable to obtain the judg¬ 
ment of a board of engineers upon the project proposed by him, and 
accordingly a board was constituted for the purpose of considering it in 
connection with other methods for the improvement of the navigable 
outlet of the Mississippi Eiver. 

The reports of the board of engineers and the report of Captain 
Howell are submitted, as follows : 

1. Eeport of Captain Howell, transmitting a project for a canal to 
connect the Mississippi Eiver below Eort Saint Philip with the Gulf of 
Mexico through Isle an Breton Pass; with appendixes marked A, B, 
C, and map marked D. 

2. Eeport of board of engineers upon Captain Howell’s project. 

3. Minority report of Colonel Barnard. 

4. Eeport of the board of engineers on the subject of the improve¬ 
ment of the passes of the Mississippi, as an alternative to or in con¬ 
nection with the canal. 





36 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


5. Minority report of Colonel Barnard. 

G. Minority report of Major Warren. 

By the method now in use for deepening the channel at the mouth of 
the Mississippi Eiver, a depth of from 18 to 20 feet at low tide can be 
maintained, which will admit vessels of 19 to 20 feet draught. 

The annual expenditure for securing and maintaining this depth 
with a width of 250 feet is $150,000, and taking into account the sum 
necessary to. supply a new steamer every four years to replace the 
worn-out one of the two in use, the annual expenditure becomes 
$ 200 , 000 . 

By doubling the annual expenditure after procuring two more steam¬ 
ers, (at a cost of $109,000,) probably a channel 100 feet wide, with a 
depth between 18 and 20 feet, could be maintained. 

This appears to be the maximum effect which may be looked for 
from the system of dredging. 

But from the experience gained in the work the officer in charge is 
of opinion that the width which can be maintained with the present 
means will be sufficient, provided the War Department can control ab¬ 
solutely the use of the improved channel, a condition essential to the 
maintenance of the improved channel, whether it be by a canal, by 
jettees, or by dredging. 

.Respecting the practicability of constructing a ship-canal from the 
river near Fort Saint Philip to the deep water of Isle au Breton Pass, 
all the members of the board agree that there is no doubt as to its entire 
practicability. 

To determine, however, the best line for the location of the canal 
across the peninsula, and the best poiut for its entering the river, and 
also the position and manner of its entering Isle au Breton Pass, re¬ 
quires further survey, borings, and other examinations and measure¬ 
ments, and the preparation of plans based upon their results. 

The board, excepting Colonel Barnard, submits an estimate of the 
cost of constructing a canal of the dimensions stated within the limits 
designated, which it believes to be ample. 

From this opinion Colonel Barnard dissents. 

Respecting the application of the jettee system to the improvenent of 
the channel at the mouth of the river, the board, Colonel Barnard 
dissenting, reports adversely both as to the difficulties attending the 
construction and the cost of the system. 

After a careful investigation of the question of applying this method 
of improvement to the mouth of the Mississippi River, I am of opinion 
that it does not present, either in its construction or cost, superior 
advantages to the canal plan. One of the chief objections to the jettee 
system is the unavoidable necessity of constantly extending the piers 
in the open sea, exposed to the full force of storms. 

Very respectfully, your obedient servant, 

A. A. HUMPHREYS, 

Br igadier-General and Ch ief of Engineers. 

Hon. W. W. Belknap, 

Secretary of War. 


FORT SAINT PHILIP SHIP-CANAL TO CONNECT THE MISSISSIPPI RIVER 

WITH THE GULF OF MEXICO. 

From the general appropriation for surveys, approved March 3,1871, 
there was allotted the sum of $10,000 for the survey of a proposed route 



IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 37 


ior a ship-canal to conuect the Mississippi River at a point near and be¬ 
low Fort Saint Philip, Louisiana, with the Gulf of Mexico, through Isle 
au Breton Pass.* 

Under orders from the Chief of Engineers United States Army, dated 
M ashington, D. C., April 18, 1871, the conduct of the survey devolved 
on the uudersigned. 

The survey was completed several months ago, but report has been 
unavoidably delayed until this time. 

Report is required on the following points: 

1st. On the commercial and national importance of the projected 
* canal. 

2d. On the feasibility of the project. 

3d. On the probable cost of construction. 

These are to be considered in the order named; the data for consider¬ 
ation being obtained from the recent survey, and from other sources 
available, which are named in the list of authorities appended. 

IMPORTANCE. 

The importance of securing an adequate outlet for the commerce of 
the Mississippi Valley is too thoroughly appreciated by the representa¬ 
tive men of the valley to require in this report more than a general 
statement. 

The valley principally depends for its development on the products 
of its agricultural population—on its grains, cotton, sugar, and its beef 
and hog products. For these there is a large European demand, the 
supply of which adds materially to the wealth and growth of the 
country. 

Active competition from other sources of supply, favored with cheaper 
labor and transportation, keeps down the market abroad, so that with 
our present means for transportation from the far interior to the sea¬ 
board the value of the product in the home-market is kept at a figure 
which does not always fairly remunerate the producer for his labor, or 
offer a stimulus to increased production. 

The advantages to be derived from works of internal improvement 
best calculated to insure the producer a better return for his labor are 
obvious. 

Railroad transportation for cheap and bulky freight over long distances 
is necessarily, and has been found by experience, too expensive to offer the 
producer hope for advantage to be gained from increase in number of 
lines and amount of rolling-stock. He has, therefore, recently turned 
attention to those known and cheaper routes overlooked during the prev¬ 
alence of the mania for railroad extension. Of these, the routes via the 
lakes, the Saint Lawrence River and Erie Canal, by the patronage be¬ 
stowed on them when not ice-bound, attest the importance of similar 
routes projected. The popular feeling in favor of water-routes from the 
interior to the seaboard is further shown by the interest manifested in 
urging the extension of the James River and Kanawha Canal, the proj¬ 
ect for a canal to connect the Tennessee River with the harbor of Savan¬ 
nah, the yearly demand for continued improvement of western rivers 
and of the bars at the mouth of the Mississippi River, and finally in this 
project for the Saint Philip Ship-Canal. 

The means for securing cheap transportation via the Mississippi River 

* This survey was directed by a resolution of the House of Representatives dated 
March 14, 1871. 



38 IMPROVEMENT OF MOUTII OF THE MISSISSIPPI RIVER. 


and its tributaries to the excellent harbor of New Orleans are promised 
by the substitution of lines of model barges, carrying large freights on 
a light draught of water, and towed by comparatively inexpensive 
steam tow-boats, for the expensive, short-lived steamboats heretofore 
engaged in traffic on those waters. The improvement of western rivers 
is yearly diminishing the risks attending their navigation. The advan¬ 
tages offered for transportation from the West to the sea, via this route, 
have attracted attention, and increasing capital from at home and 
abroad, and there is now every reason to expect that these great natural 
highways will become, as they ought to, the commercial routes connect¬ 
ing the Mississippi Valley with the eastern seaboard and with foreign 
countries. 

That this desirable end may be attained it is first necessary to assure, 
beyond matter of doubt, adequate entrance to the Mississippi, at all 
seasons of the year, for sea-going vessels of the largest freighting ca¬ 
pacity requisite to afford the cheapest freights. 

Congress has heretofore, with yearly increasing appreciation of this- 
necessity, and recently with increased liberality, fostered the various 
plans presented for giving such entrance. The results have been such 
as to warrant yet more liberal action. 

With the success attending the work of dredging the bar at South¬ 
west Pass during the past two years, the commerce seeking the port of 
New Orleans has grown rapidly. 

Lines of steamships before in the trade have built new vessels for it y 
other old lines have been attracted to it; new lines have their vessels in 
course of construction ; and sailing-vessels, in greater number than be¬ 
fore, have engaged in it, all taking fuller cargoes, making quicker trips, 
with greater i)rofit to owners and reduced expense to shippers. The 
cotton-trade of the upper cotton region, for a time partially diverted 
from this route, is returning, and a grain-trade has been inaugurated, 
which promises to attain large proportions. 

While the great benefit already derived from dredging is acknowl¬ 
edged, there remains, in the minds of commercial men, doubt as to its- 
continuance to meet the growing demand for deeper-drauglit vessels. 

There is yet more serious doubt regarding the continuance of suita¬ 
ble action on the part of Congress in making appropriations seasonably 
and in amount to prevent interruption of the work. 

Distrust in the continued effectiveness of dredging can only be over¬ 
come by long-continued success, and simply retards commercial prog¬ 
ress. Distrust in the continued good-will of Congress is of more serious 
import. 

The work in progress is dependent for its continuance on an annual 
appropriation; it is of a character requiring continued work; suspen¬ 
sion for a few weeks or months will permit the natural agencies always 
at work to obliterate all evidences of previous improvement and return 
the channel across the bars at the river outlets to their normal and ob¬ 
structed condition. Such occurrence would be disastrous in the extreme. 
It would ruin the commerce now promising such good results, ruin the 
merchants engaged in it, and destroy confidence in plans for its revival 
at any future time. Yet such occurrence is not improbable, as evidenced 
by the past record of the work. 

Legislative economy enters too largely into the spirit of American 
politics to permit of men engaged in legitimate business staking their 
wealth where it will depend on the turn legislation may take. 

What is required to inspire confidence in the future of the commerce 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 39 

of the Mississippi River is a permanent outlet, not one of uncertain 
tenure. 

Dredging, from its dependence on legislative action, does not offer 
such, nor do I believe it capable of offering more than a depth of 20 
feet the year round, a depth not considered adequate. It is conceived 
that this canal project does. The magnitude of the interests involved 
appears to warrant a trial of the project. 


THE PROJECT. 

The project for this canal has been agitated for the past forty years. 
It has had its advocates principally among local engineers and mer¬ 
chants, but has been recommended by higher authorities as a final re¬ 
sort should dredging fail or ultimately prove inadequate to fully meet 
the growing wants of commerce. Its feasibility has never been made 
the main subject of discussion or objection, but it has always been dis¬ 
carded on the ground of its supposed cost, estimated greater than the 
amount of commerce it was designed to aid was presumed to warrant. 
This objection lias now lost the force it once had, and if at all consid¬ 
ered, can have no special weight in deciding for or against the construc¬ 
tion of the canal. 

The question of feasibility is the only one requiring consideration. 
To settle this, and at the same time gain the information required for 
making plans and estimates for the canal,'has been the object of the 
recent survey. 


PREVIOUS SURVEYS. 


A reconnaissance of Breton Island Pass made by British naval offi¬ 
cers about 1775, the results of which were made public, (*in chart sub¬ 
mitted,) though made for other purposes, affords the earliest known 
data bearing on the project. 

An examination is reported to have been made by Maj. Benj. Buis- 
son, State engineer of the State of Louisiana, about 1832, on the results 
of which Major Buisson appears to have originated and recommended 
this project by his reports, giving to it, at that time, considerable prom¬ 
inence. Outside of bare mention in reports and correspondence of later 
date, I have found nothing to show that Major Buisson made more than 
a simple examination on which to base his project. 

The representations of Major Buisson, supported by the action of the 
legislature of Louisiana and of the Chamber of Commerce of New Or¬ 
leans, induced Congress to authorize an investigation of the project. 
This was made early in 1837 by Capt. Wm. H. Chase, Corps of Engineers, 
U. S. A., who reported favorably, t This report was based on a hurried 
reconnaissance, and was not considered satisfactory. In consequence, 
a survey was ordered in 1838, and made under the direction of Capt. 
Andrew Talcott, Corps of Engineers, U. S. A., the plot of which is sub¬ 
mitted. (Chart C.) 

The report of Col. J. J. Abert, chief topographical engineer,! based 
on the results of this survey, caused the abandonment of the project by 
Congress. 

In 1858 Mr. R. Montaigu, civil engineer, revived the project, made 
an examination, (the character of which I have not been able to ascer- 

* Not published until 1823. Enlarged copy of chart submitted, marked I). 
t See Ex. Doc. No. 173, House Reps., 24th Cong., 2d session, 
t See Ex. Doc. No. 2, page 681, vol. 1, 26th Cong., 1st sess. 



40 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


tain,) and published a voluminous pamphlet (copy submitted, marked 
H) in support of his views. The death of Montaigu and the outbreak 
of the rebellion suspended consideration of the project. 

In 18G9, the Coast Survey extended its work to cover Isle au Breton 
Pass, (chart submitted, marked C,) the results of which agree with 
those obtained by our survey. The project was finally brought to the 
attention of Congress during the winter of 1869-70, by prominent mer¬ 
chants of New Orleans, and the undersigned directed the report on its 
feasibility. Such report was rendered, based on the results of a per¬ 
sonal reconnaissance, and represented the necessity for making a more 
thorough survey than had yet been made. Such survey was directed, 
completed, and its plot is submitted, (marked A.) 

THE SURVEY. 

The field-work was commenced November 8, 1871, and concluded 
March 13, 1872. The instruments used were of Wtirdemann’s and Gur¬ 
ley’s best make. The assistants employed were skilled in the duties 
assigned them. 

Lieut. H. M. Adams, Corps of Engineers, United States Army, was 
placed in charge of operations in the field, and has made many of the 
computations for dimensions and cost of construction. 

After measurement of a base and completion of the primary triangu¬ 
lation, the party was divided into three. 

Assistant F. M. Eppley was put in charge of all hydrographic work, 
Assistant Thomas Larkin in charge of topography and leveling, Assist¬ 
ant W. Lanuegan in charge of boring party. 

The results of the survey are displayed on Chart A, as given in the 
following statement: 

Breton Island Pass .—This is the western of the two passes connecting 
the large body of water known as Breton Island Sound with the Gulf 
of Mexico. Its minimun width is about 33,000 feet; iniuimuin area of 
cross-section about 536,000 square feet.; maximum depth in throat of 
pass, 36 feet at mean low tide; and depth over the bar at the mouth of 
the pass, 28 feet. The axis of the pass lies nearly southeast and north¬ 
west. The Gulf approach is from the southeast, and is flauked on the 
one side by the Chandeleur Islands, Errol Islands, and Isle au Breton ; 
on the other by the land forming the east bank of the Mississippi River, 
the two flanks forming with each other nearly a right angle, having the 
pass at the vertex. 

The approach is well covered except from the southeastward, and 
offers abundant room and good holding-ground for the anchorage of a 
large fleet. The bottom is soft and sticky in the deeper portions of the 
pass and approach, and hardens from the twenty-foot curve toward the 
shore-lines. The islands are of sand, and the Mississippi shore line an 
alluvial, marshy formation, fringed with sand-reefs. At its head the 
pass expands abruptly into Breton Island Sound and shoals rapidly. 

The great depth of the pass is due to the tidal currents through it. 
Observations were made to determine the velocities of these currents, 
floats being used for the purpose, but with such unsatisfactory results 
as to make them valueless. 

A computation has been substituted, based on the record of tide- 
gauge kept at Sable Point, (diagram submitted, marked F,) the mini¬ 
mum area of cross-section of pass, (section submitted, marked F F,) and 
the superficial area of that portion of Breton Island Sound affected by 
the tides through the pass, (see appendix marked G.) “It is best to 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 41 ’ 

use such calculations only for the purpose of computing the probable 
effect of alterations.”—(Rankiue.) It is for this purpose alone the infor¬ 
mation is required. 

By these computations for the time covered by the gauge-record the 
velocity of the inward or flood-tide current was found to range from 
zero to 1.06 fest^ per second; that of the outward or ebb-tide current 
from zero to 1.75 feet per second. Higher tides than those observed 
have been known to occur, but. they were of longer continuance than 
any shown on diagram, and it is possible caused no stronger flood-cur¬ 
rent than is shown, but a stronger ebb-current. No reliable information 
could be obtained regarding these extraordinary tides from which to 
determiiiQ the rise and fall that would have been indicated by the Sable 
Island gauge. It is only known that they seldom occur, are caused by 
southeast hurricanes, which continue for two or three days, and that 
during their continuance water from the Gulf has been known to flow 
into the river, over the lower portions* of the river bank, below Fort 
Saint Philip. 

The portion of Breton Island Sound daily filled and discharged 
through Breton Island Pass has a superficial area of water-surface of 
about three hundred and five square miles. Its northern and western 
shore-line is covered by numerous small islands and oyster-reefs, and 
indented with bays and bayous connecting with lakes in the Lake 
Borgne Peninsula. The depth of water in the sound ranges from 15 
feet at the head of the pass to a few inches at the shore-line. The 
bayous connecting the lakes with the sound have a depth of from 20 to 
30 feet. The lakes are shallow. The shores and bottom are of alluvial 
formation ; the islets generally of sand. There are no streams entering 
into the sound, and no connection with the Mississippi River, even dur¬ 
ing the season of high water in the latter, the levees, which extend to 
Fort Saint Philip, effectually cutting off such communication above the 
head of Breton Island Pass. 

Outside of the pass, and at the foot of the Fort Saint Philip Peninsula, 
there is a break in the river-bank known as Cubit’s Gap, through which 
the Mississippi River makes its first discharge to the eastward. This 
discharge is only during the flood-stage of the river, and during this 
stage much material in suspension is carried through the gap from the 
river to be deposited in Bird Island Sound, some of which may find its 
way into Breton Island Sound, as is hereafter explained. 

The next eastward outlet of the river is through the a Loutre Passes 
and the numerous small bayous branching from them. These outlets 
are so situated in relation to Breton Island Pass, as will be seen by 
reference to a map of the Mississippi delta, that, during the prevalence 
of southerly winds, some of the muddy water discharged through them 
must be carried by the littoral current, induced by such winds, in the 
direction of the pass, and not only cause deposit in the bayous of the 
Saint Philip Peninsula, but on rare occasions, by extending into Breton 
Island Sound, cause slight deposits there, tending, at some time in the 
very remote future, to materially lessen the capacity of the sound as a 
tidal reservoir. 

The Saint Philip Peninsula, through which it is proposed to carry the 
trunk of the canal, is entirely (with the exception of the Sand Islands 

* The difference between the lowest and highest tides observed by this survey was 
3.70 feet. (See Fort Point gauge, diagram F.) The greatest difference observed in 
1851 and January, 1852, in Eayou Saint Philip, was 4.92 feet. See Humphreys & 
Abbot’s Physics and Hydraulics of Mississippi.) The first-nanu;d gauge was the 
entrance to the bayou, the second at the head. The modifying action of the bayou 
could not be ascertained, the old bench-mark at Fort Saint Philip having been lost. 



42 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


skirting its eastern border) of alluvial formation, tlie character of which 
is shown by the borings, sections of which are shown oil Chart A. 

The greater part of the peninsula is covered by shallow bays and 
lagoons, the only firm land being a narrow strip along the river-bank, 
and that afforded by the Sand Islands. The formation is entirely simi¬ 
lar to that on which the city of New Orleans and the heavy structures 
of Forts Jackson and Saint Philip are built. 

The river, for several miles of its length along the reach available for 
the river end of the canal, is nearly straight, and the water deepens 
rapidly from the shore-line. The banks are stable because through this 
reach the river-current is parallel to them, and has not sufficient veloc¬ 
ity to further abrade them, as it does in the bends above. 

The range of the river between extreme low and extreme high water 
was found to be about G feet by reference to gauge-record kept at Fort 
Jackson during the past year. This has been adopted as the extreme 
lift of the river-lock for the canal, the least being zero. 

The facts above stated, together with those referred to as displayed 
on charts and in appendixes submitted, are all that are required for the 
discussion of the feasibility of the project for this canal. 

DISCUSSION OF FEASIBILITY. 

The feasibility of the project depends, first, on finding Breton Island 
Pass, in its present condition, not subject to material deterioration as 
regards depth and other dimensions, within such reasonable period of 
time as may be assumed sufficient to repay, in the benefit commerce 
may derive from the canal, the cost of its construction. Of this we are 
to judge, first, from the charts of past surveys, the earliest of which, 
fortunately, dates back quite one hundred years. Four of the charts are 
presented, reduced to the same scale for ease of comparison, and will be 
found marked A, B, C, and D. Though the soundings on these are not 
referred to the same plane, (being referred to mean low tide as deter¬ 
mined by observation made during the continuance of the surveys which 
they separately represent,) from the manner in which the plane of refer¬ 
ence was obtained in each case there can be but such slight difference 
that we may ignore it and compare the soundings as if referred to the 
same plane. 

Making the comparison, we find there has been, within the past one 
hundred years, no noticeable change in the depth of water over the bar 
at the entrance to the pass, and that the entrance has, if anything, im¬ 
proved by widening. We fiud the depth in the throat of the pass main¬ 
tained, and but unimportant chauges in the contour of the head of the 
pass, where it spreads out into Breton Island Sound. From inspection 
of the charts, the conclusion must be such as to warrant belief that no 
greater changes will be observed during the next one hundred years 
unless new causes for change are introduced. 

Let us consider the possibility from new causes. 

The dimensions of the pass are determined by the volume and velocity 
of the tidal currents through it. These are dependent chiefly on the 
area of the reservoir to be daily supplied and depleted through the 
pass. 

So long as this reservoir (the west end of Breton Island Sound, and 
the bays, bayous, and lakes connecting with it) retains its present area, 
there can be no change resulting from natural causes alone in the dimen¬ 
sions of the pass. That this area cannot be materially diminished by 
silting, is evident from the following: 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 45 


The ebb-current through the pass being always stronger than the 
flood-current, is able to return to the Gulf the greater part of what silt 
may be brought by the flood-current from the eastern outlets of the 
Mississippi River. These outlets are at a considerable distance from 
the pass. The present indications are that the nearest is filling, and we 
know that the others are pushing out farther into the Gulf, increasing 
their distances from Breton Island Pass. There is no reason to appre¬ 
hend the formation of new outlets above the present ones. Should there 
be, at any future time, cause for apprehending breaks in the river-bank 
that might result in injury to the pass, comparatively inexpensive levees 
can be built to effectually guard against them. 

As before stated, there are no streams emptying into the sound, and 
the Mississippi River is securely leveed. There can be no silt brought 
in from that direction, except through a possible crevasse. There can 
be no silt brought in from the northeastward through Chandeleur Sound, 
since the tides through Grand Gosier Pass effectually cut it off. Pilling 
of the sound by the gradual growth of oyster-beds and reefs is barely « 
considerable. 

Since existing sources of silt are being blocked up or further removed, 
and since possible new sources can be easily guarded against, I conclude 
that the area of Breton Island Sound will remain as now for an indefi¬ 
nite time, and the dimensions of Breton Island Pass remain unchanged 
from natural causes. 

The constructions (the jettees) required to carry the debouche of the 
canal to the deep water of the pass will cause changes, the general char¬ 
acter of which may be predicted. 

The area of cross-section of the pass will be diminished by the con¬ 
struction of the jettees proposed by 70,000 square feet. 

The area of Breton Island Sound remaining unchanged, the volume of 
water going through the pass to fill or deplete the sound daily will be, 
after the jettees are built, the same as if they were not constructed. This 
will cause increased velocities of the tidal currents and* increased scour 
of the bottom, and of the Breton Island side of the pass, until such time 
as the present area of cross-section is restored. 

The axis of the pass will be shifted to the eastward and its direction 
slightly changed. The contour of the head of the pass will be consider¬ 
ably changed, and the west end of Breton Island will probably, consid¬ 
ering the character of its formation, be abraded unless protected by 
works of art. 

From the character of the bottom in the deeper portions of the pass, 
it is probable the pass will regain its normal dimensions entirely at the 
expense of the Breton Island side. Unless the end of the island is pro¬ 
tected with such protection as may be necessary, the pass will deepen. 

The extent of the changes which the jettees will effect can only be defi¬ 
nitely ascertained after the construction of the latter. Injurious changes 
may be prevented by the protection of the west end of Breton Island, as 
may be found necessary in the course of construction. 

While the effect of the proposed jettees on the east side of the pass 
cannot be accurately predicted, their effect on the west side, on Sable 
Island, may be predicted with certainty. The angles between the shore¬ 
line and the jettees will partially fill with sand and other deposits. 
This has been the experience of engineers with all jettee constructions 
on our northern lakes, on our Atlantic seaboard, and in Europe ; at the 
mouths of the Oder, the Vistula, and the Danube, and, recently, at the 
debouche of the North Sea Canal and of the Suez Canal. In all these 
cases this filling is considered objectionable, inasmuch as the tidal cur- 


j 


44 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

rents (shore-currents) perpendicular to the jettees are not strong 
enough to prevent the ultimate growth of the shore-line incident to this 
filling from extending around the jettee-head and obliging an extension 
of the jettees themselves. In the case under consideration, it is possi¬ 
ble to secure a very strong current passing the jettee-heads, sufficient 
to insure us against apprehension of being called upon at any time to 
extend our constructions. 

As there will be no current through the canal, we must expect silting 
immediately between the heads of the jettees, due to eddies from the 
currents through the pass. It is apprehended that shoaling of the en¬ 
trance to the canal from this cause will not be rapid, but that there will 
be required, to free the entrance from such deposit as may be made, each 
year, the services of an ordinary dredge-boat for several days, or per¬ 
haps weeks. 

In the trunk of the canal there will be no silt admitted, the proposed 
arrangement of sluices for the lift-lock being such as to keep all river 
water required for the lift from passing into the canal below the lock. 

Slight deposit is anticipated within the lock, the removal of which, 
quarterly or semi-annually, will be a very simple operation. 

There will be deposit of river-silt in the fore-bay of the lock, due to 
an eddy from the river-current. The amount of this deposit cannot be 
calculated, and it will require occasional dredging to maintain the depth 
of this entrance to the canal. 

The river-bank at the point selected for the head of the canal, as 
before stated, is not subject to change, and the depth of the river-bed 
may be expected to very gradually increase with the advance of the 
mouth of the river gulfward. 

In conclusion, I can see no reason from the above to question the 
feasibility of the project, as it has heretofore been questioned, on the 
assumption of engineers, that Breton Island Pass will deteriorate and 
the canal itself fill with silt to such an extent as to require continued 
extensive dredging to keep it open. 

In regard to the foundations for locks, reference is made to the sec¬ 
tion of borings (Chart A) and to the specimens sent herewith. 

Borings numbered 1, 2, and 3 show, at a suitable depth for the foun¬ 
dation of a sift-lock, a stratum of mud-lump clay, having an indicated 
thickness of over 20 feet, and its further thickness not ascertained. 
This I consider well calculated to sustain the lock shown by drawings 
submitted, if a solid timber platform, here recommended, is employed, 
or even if a pile and grillage foundation should be adopted. 

As no plan of founding will be adopted, even should the construction 
of the canal be decided upon, except under the advisement of a board 
of engineers, it is not essential that I should here give reasons for favor¬ 
ing the platform. 

Boring No. 6, in my opinion, shows that a good foundation may be 
had for the guard-lock on Sable Island. 

Excavation for trunlc of canal .—This will be the least difficult part 
of the work to execute. It will be entirely through an alluvial forma¬ 
tion, free, so far as has been ascertained, from rocks, stumps, and buried 
timber. It can all be done by dredge-boats, provided with suitable car¬ 
riers to transfer the spoil to the banks. 

Canals* have been successfully carried through a similar formation by 
allowing the excavation of a large cross-section with easy slopes, anil 
by giving the embankments a wide base as compared to their heights. 
The cross-section of this canal and embankments must be determined 


* North Sea Canal of Holland. 



IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 45 

wliile excavation is in progress, and be varied to soit the peculiarities of 
the formation found in the several sections of the work. 

For purpose of estimate, a uniform cross-section* has been assumed 
with sides given, the slope found in the river at the head of the canal. 
The embankments of the canal at some points may require protection 
of their outer slopes by faciues or wicker-work, or by a growth of wil¬ 
lows. Throughout their greater part, sodding with Bermuda grass will 
be sufficient to prevent washing of the slopes. Washing of the sides 
of the excavation may be avoided by introducing the towage system 
of navigation now in use on the Biver Seine, in France, and Elbe, in 
Germany, which, I think, will be better and more economical than a 
railroad and towing-locomotives on the embankment. 

The jettees .—The location of these is shown on Chart A. The founda¬ 
tion available is shown to be a good one. Similarly-constructed jettees 
have been employed at the Salina, mouth of the Danube, proving effi¬ 
cient, substantial, and economical. 

There can be no doubt of the ability of even an engineer of ordinary 
capacity to construct these jettees in the manner indicated by the draw¬ 
ings, so as to withstand the strongest seas to which they may be ex¬ 
posed. The dimensions adopted for the purpose of estimate may require 
modification in the course of construction, as they are based on calcu¬ 
lations having factors the value of which could not be accurately de¬ 
termined. 

PLANS FOR CONSTRUCTION. 

The general and detailed plans for the various constructions pertain¬ 
ing to the canal, and herewith submitted, were drawn up more for the 
purpose of estimate than with a view to their ultimate adoption with¬ 
out modification. They have been as carefully considered as the time 
at my command for such purposes would permit. 

While some points of the plan are original, the greater number, it 
will be observed, have been adopted from existing works; for example, 
the general plan and details for gates, &c. (Due acknowledgment will 
be found on the drawings.) In all such cases dimensions have been 
changed to suit the new conditions imposed. 

The drawings are intended to be so complete as to render a detailed 
description unnecessary. 

GENERAL DESCRIPTION. 

The lift-lock is 400 feet in length between gates, 80 feet wide at top, 
and has a depth of 27 feet over the sill at mean low tide in the Gulf. 
The side walls and bottom are of beton, the walls faced with granite. 
These are founded on a solid timber platform, Gfeet in thickness, extend¬ 
ing the whole length and breadth of the lock, composed of layers of 12 
inch by 12 inch squared timber alternately crossed at right angles and 
bolted together in the manner adopted for the caissons for piers of the 
East Biver suspension bridge, the whole forming a rigid beam calcu¬ 
lated to uphold without deflection the weight of the superstructure. 
This foundation rests upon a stratum of mud-lump clay known to be at 
least 20 feet in thickness. Seepage is cut off by rows of close piling ex¬ 
tended from the lock GO feet into the bank. The platform is surrounded 
by a double row of close piling, the heads of the piles being strongly 
strapped to the platform. 


* Width at bottom, ‘200 feet; depth, 27 feet; slope, 1 on 2. 




46 IMPROVEMENT OF MOUTII OF THE MISSISSIPPI RIVER. 


The gates are of iron, circular in plan, and of the kind known as 
floating gates. Their floatation is calculated, without ballast, for a 
draught of 28.J feet, and for greater depths water-ballast will be intro¬ 
duced or discharged, as may be made necessary by the fluctuations of 
the tides. The miter-sills are wronght-iron trusses. The opening and 
closing of the gates will be effected by chains and hand-winches. 

The sluices for filling and emptying the lock are large cast-iron pipes, 
laid in the side walls just below the level of extreme low water in the 
river. Water is received from the fore-bay to fill the lock, distributed 
by branch-pipes the whole length of the lock-chamber, then sluiced out 
through the same pipes into open ditches on either side of the canal. 
By this method the purest water obtainable from the river is sluiced in 
on the cushion of salt water already in the lock, and its specific gravity 
being less than that of the latter, it remains long enough on top to be, 
with the greater portion of its impurities, sluiced outside of the canal. 

The sluice-gates are arranged with hydraulic lift, and are lowered by 
their own weight. 

The lock is located 400 feet from the river-bank. The approach to it 
is between two timber wharves, which, besides forming the sides of the 
entrance, are extended on either side several hundred feet along the 
river-bank, for the convenience of vessels waitiug to pass the lock or 
awaiting towage to New Orleans. The lower approach is similarly ar¬ 
ranged. 

All the piles used in this and in other structures are to be corbelized 
by the Seeley process. 

The guard-lock is entirely similar in design and construction to one 
eud of the lift-lock. It is intended to close the canal on occasions of ex¬ 
traordinary storms, which raise the water in the Gulf higher than that 
in the river. 

The details adopted for the jettees are well enough shown by the 
drawings. 

The construction is one of a substantial, though temporary, character, 
and must ultimately be superseded by one of beton, based on the foun¬ 
dation this will afford.* 


ESTIMATES. 

The estimates presented have been based on the cost of material and 
labor for small works undertaken in the neighborhood of the proposed 
canal. 

The magnitude of this work will apparently justify belief that ma¬ 
terial may be obtained at less cost than that estimated. It is also evi¬ 
dent that the material used for coffer-work may be taken up and used 
in other parts of the work. 

These considerations induce me to leave out of my estimate amounts 
required for engineering, superintendence, and contingencies. 

With this explanation the following estimates are submitted: 

Estimate. 

For excavation of trunk of canal and sea entrance. 

For construction of lift-lock. 

For construction of coffer for same. 

For construction of jettees. 

For construction of guard-lock. 

For construction of coder-work for same. 

For construction of wharf and excavation at river entrance 

' The reason for adoption of this character of structure is, that it will be economical 
and can be constructed sooner than permanent jettees. 


$3,960, 673 50 
750, 900 00 
250,938 82 
1,949,497 70 
226,885 80 
118,068 28 
107,839 48 













Oi tU CO Ki i—* 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 47 


SUMMARY. 


Excavation of trunk. 

. Construction of lift-lock. 

. Construction of coffer for same. 

. Construction of jottees. 

. Construction of guard-lock.. 

6. Construction of coffer for same. 

7. Construction of wliarf aud river entrance 


$3, 966, 673 50 
750,900 00 
250,938 82 
1,949,497 70 
226,885 80 
118,068 28 
107, 839 48 


Grand total 


7,370,803 58 


SUMMARY OF CONCLUSIONS. 

1st. The construction of the canal is a matter of great importance. 
2d. The project is feasible, and its execution presents no great diffi¬ 
culties to be overcome by the engineer. 

3d. The total estimate of cost approximates $7,400,000, in round 
numbers. 


TIME REQUIRED FOR COMPLETION. 

If suitable appropriations are made, the work can be completed within 
three years of the date of its commencement. 

To do this, an appropriation of $3,000,000 should be made available 
for the first year, $3,000,000 for the second year, and the balance for 
the third year. 

Should completion be delayed a longer time than three years from 
date, a new dredge-boat will be required, at an expense of about 
$250,000, to continue the work of dredging at the mouth of the Missis¬ 
sippi River, maintaining its present effectiveness. 

The cost of construction will be increased. 

Respectfully submitted. 

C. W. HOWELL, 

Captain of Engineers, United States Army. 

L t nited States Engineer Office, 

Few Orleans , La ., February —, 1873. 


LIST OF SPECIAL AUTHORITIES CONSULTED. 

To ascertain importance of the project. 

Statistics from the Bureau of Agriculture, made available through 
newspaper publications. 

Commercial statistics from reports of various commercial bodies. 

Report of the Chief of Engineers for 1871, pp. 632-3, &c. 

Pamphlet compiled by E. Lorraine, chief engineer James River and 
Kanawha Canal Company, published by the company in I860. 

Reports of Chief of Engineers, United States Army, since 1867. 

To ascertain feasibility. 

For character of Breton Island Pass, survey ot 1871- 72, Chart A, 
submitted; Coast Survey chart, 1869, Chart B, subnutted; Talcott’s 
survey, 1837, Chart C, submitted; reconnaisances 1775-76, published 
1823, Chart D, submitted. 












48 IMPROVEMENT OF MOUTII OF THE MISSISSIPPI RIVER. 


For character of formation of Fort Saint Philip Peninsula and of 
Breton Island, charts above referred to, reports of various engineers, &c. 

Sections displayed on Chart A. 

Specimens* of borings in boxes herewith. 

Tides through Breton Island Pass. 

Observations made 1871-72 at Sable Island. Diagram submitted, 
marked F. 

Observations at Fort Point. Record submitted. 

Observations in Bird Island Sound. Record not submitted. 

Observations in Lucas Canal. Record not submitted. 

Currents through Breton Island Pass : 

Velocity computed, and computations submitted in appendix, marked 

G. 

Velocity computed for increase due to construction of jettees. (See 
Appendix G.) 

Rise and fall of the Mississippi River : 

Humphreys and Abbot. Gauge-record at Fort Saint Philip in 1851. 

Gauge kept at Fort Jackson, 187l- 7 72. 

Effects of severe storms; from statements of residents below Fort 
Saint Philip. 

Effects of waves and tidal currents on jettees, &c. 

Stevenson on Harbors. Foundations on compressible soils. 

Memoir of General Richard Delafield, United States Army, published 
by order of Light-House Board, December 1, 1868, and several of the 
authorities cited by the author. 

Report of Bvt. Maj. Gen. J. G. Barnard, Corps of Engineers, United 
States Army, on the North Sea Canal of Holland. 

London Engineer, 1872-’73, on same. 

Personal observations and experience. Excavation through com¬ 
pressible soils. 

Personal observations in New Orleans, at the Mexican Gulf Canal, 
and on the coast of Texas. 

Reports regarding excavations for the North Sea Canal of Holland. 

Reservation of timber. Report of T. J. Cram, Colonel of Engineers 
and Brevet Major-General, United States Army, published by Engineer 
Department, 1871. 

Report made to the board of public works, Washington, D. C., 1872. 

Construction of timber jettees. Professional Papers Royal Engineers, 
Vol. XIII, new series, Paper V. 

Report of United States engineer on improvement of lake harbors ; 
construction in beton. 

Professional Paper 19, Corps of Engineers, United States Army. 

Various reports on application of locks and jettees in Germany and 
England. 

Experience at Forts Jackson and Saint Philip. 

Previous reports and opinions of engineers and others in relation to 
the project. 

Ex. Doc. No. 173, House of Representatives, 24th Congress, 2d session. 

Vol. VII, p. 463, Ex. Doc. 26th Cong., 1st session. 

Vol. I, p. 684, Ex. Doc. 26th Cong., 1st session. 

Reports, &c., printed by Chamber of Commerce of New Orleans in 
1837. 

* Specimens not forwarded. In making arrangements for packing it was found that 
many of the labels had fallen off and been misplaced, so that but few of the specimens 
could be identitied with certainty. 






IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 49 

Humphreys and Abbot. Physics and Hydraulics of the Mississippi 
River. 

Project of R. Montagu, chief engineer, 18G9. Copy submitted, 
marked H. 

Memoir of Win. M. Burwell, esq. Copy submitted, marked I. 


List of maps and charts submitted. 

A. Chart of survey, 1871-72. 

B. Coast Survey chart, 1809. 

C. Taleott’s survey, 1837. 

D. Rec. 1775, &c/ Pub. 1823. 

Plate I. Plan, section, and elevation of lift-lock. 

Plate II. Details of lift-lock. 

Plate III. Lower approach to lift-lock. 

Plate IV. River approach to lift-lock. 

Plate V. Details of coffer-work for lift-lock. 

Plate VI. General plan of guard-lock and approaches. 

Plate VII. General plan of jettees, sections of same, and details of 
jettee-heads. 

F. Diagram of tide-observations. 

F F. Sections of Breton Island Pass. 


H. Ex. 220-4 




APPENDIX. 


A. 

To compute the velocity of tidal currents through Breton Island Pass. 
Given : 

1. Tide-gauge record at Sable Point for December, 1871, January and 
February, 1872. 

2. Minimum cross-section of the pass. 

3. Area of portion of Breton Island Sound affected. 

[Computation by First Lieutenant C. E. L. B. Davis, Corps of Engineers, United 
States Army.] 


Notation and formula. 


t 


Y=velocity of current in feet per secoud. 

«=area of reservoir, 305 square miles. 

Ji =rise or fall of each observed tide, in feet. 
t=time between high and low water, each tide. 
b =area of cross-section of pass, 536,000 square feet. 
ah =quantity flowing through in time t. 

I—=quantity flowing through in unit of time. 
t 

ah 


t __ali_ a 
b ~~bt b 


Constant factor, 


h 

t 

a 

3600 s b 


305X27878400 
3600x 530000 


EBB. 

FLOOD. 

T)n.v of flip, month. 

Value of t 

Value of h 

Velocity in 

Value of t 

Value of h 

Velocity in 


in hours. 

in feet. 

feet per sec. 

in hours. 

in feet. 

feet per sec. 

u. 

12. 0 

1.6 

0. 5876 

12.0 

1. 97 

0. 7234 

12. 

11.5 

2. 47 

. 9464 

13.0 

2. 6 

.8813 

13. 

9.0 

2.4 

1.1751 

12.0 

2.9 

1. 0649 

14. 

13.0 

2. 1 

.7118 

9.0 

1.8 

.8813 

15. 

13.0 

2.2 

.7457 

11.5 

1.7 

. 6514 

16. 

12. 0 

1.8 

.6609 

11.0 

1.9 

. 7611 

17 . 

9.8 

1.6 

.7834 

10.0 

1. 4 

.6619 

18 . 

6. 5 

0.9 

.6101 

6.0 

0.6 

. 4406 

19 . 

8.5 

0.6 

.3110 

7.0 

0.6 

.3777 

20 . 

2.0 

0. 3 

. 6609 




22 . 

10. 0 

1.3 

.5728 

12.5 

1.7 

.5993 

23. . 

10.0 

1.6 

.7051 

10.0 

1.2 

. 5288 

24. 

10.0 

1.7 

.7491 

11.5 

1. 45 

. 5556 

25. 

10.0 

1. 75 

.7712 

12.0 

2.8 

1. 0282 

26.. 

8.0 

1.7 

. 9364 

10.5 

1.5 

.6295 

•27 ... . 

11.5 

2.0 

.7664 

12.5 

2.5 

.8813 

28. - - 

7.0 

1.8 

1.1331 

11.5 

1.5 

. 5747 

•29.. 

10.0 

1.9 

. 8372 

10. 7 

1.8 

.7413 

30. 

10.0 

1.7 

.7491 

9.0 

1.5 

.7344 

31. 

9.0 

1.4 

.6854 

11.0 

1.1 

.4406 

Sum...... 



15. 0987 




Mean . 



.7549 



.6925 































































IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 51 

JANUARY, 1872. 


EBB. 

FLOOD. 

Day of the month. 

* 

t. 

h. 

Y. 

t. 

h. 

Y. 

1 . 

10. 0 

2. 2 

0. 9694 

9 5 

1. 4 

0. 6494 

2. 

8. 5 

0. 8 

. 4174 

9. 0 

0. 6 

. 2937 

3. 

10. 5 

0. 8 

. 3357 

7. 5 

0. 75 

. 4406 

4. 

12. 0 

0. 55 

. 2019 

8. 5 

0. 57 

.2955 

5. 

8. 5 

0. 57 

. 2955 

9. 0 

0. 9 

. 4406 

6. 

10. 0 

1. 0 

. 4406 

8. 7 

1. 2 

. 6078 

7. 

8. 8 

2. 1 

1. 0515 

14. 5 

2. 33 

. 7081 

8. 

9. 4 

2. 13 

. 9985 

12. 0 

2. 4 

. 8813 

9. 

11. 3 

2. 6 

1. 0139 

13. 0 

2. 4 

. 8135 

10. 

9. 5 

2. 52 

1. 1689 

10. 5 

2. 42 

1. 0156 

11. 

9. 5 

2. 5 

1. 1596 

11. 5 

2. 4 

. 9196 

12. 

9. 0 

2.12 

1. 0379 

10. 7 

2. 02 

. 8319 

13. 

12 . 0 

2.1 

. 7711 

10 . 0 

1. 75 

. 7711 

14. 

11 . 0 

0. 95 

.3805 

8 . 8 

1. 15 

. 5758 

15 . 

12. 5 

1. 45 

. 5112 

8 . 0 

0 . 6 

. 3305 

16. 

8 . 0 

0.4 

. 2203 

11.0 

0. 4 

. 1602 

17 .:. 

1 . 0 

0.2 

. 8813 

13. 0 

0. 85 

.2881 

18 . 

10 . 0 

0. 95 

. 4186 

11 . 0 

1.0 

. 4006 

19. 

10.7 

0. 95 

.3912 

12.0 

0. 85 

. 3121 

20 . 

10.0 

0. 85 

.3744 

10 . 0 

1.27 

.5596 

21 . 

12.0 

2. 15 

. 7895 

10.5 

1.33 

.5581 

22 . 

9.5 

1.63 

.7561 

12 . 0 

2 . 08 

.7638 

23 . 

8.5 

1.95 

1 . 0109 

13.5 

2 . 1 

.6854 

24 . 

8.2 

1. 64 

. 8813 

13.0 

2.24 

.7593 

25 . 

8 . 5 

1 . 6 

. 8295 

14.3 

2 . 22 

.6841 

26 .. 

9.0 

2.22 

1. 0869 

14.0 

2.0 

.6295 

27 . 

10. 5 

1.7 

.7134 

10.2 

1. 4 

.5875 


9.5 

1.83 

. 8488 

10. 7 

0. 95 

.3912 

29 . 

10.0 

1.24 

.5464 

10.0 

0.72 

.3173 


12.0 

0.8 

.2937 

12.0 

0.5 

.1836 


1.0 

0.1 

. 4406 

15.0 

1.3 

.3819 




21. 2338 



17. 2373 




0. 6849 



0. 5560 









FEBRUARY, 1872. 



1.5 

0.2 

0. 5875 

6.5 

0. 4 

0. 2712 


12.0 

1.0 

.3672 

8.0 

0.6 

.3305 


12.0 

1.8 

.6609 

8.5 

1.1 

. 5702 


9.0 

1. 4 

.6854 

10.0 

1.6 

.7051 


8.5 

1.8 

. 9331 

14.3 

3.13 

.9645 


9.8 

2. 43 

1. 0926 

12.9 

1.9 

.6490 


9.0 

1.9 

.9303 

13.0 

2.34 

. 7932 


10.0 

2. 54 

1.1192 

15.0 

2.2 

.6463 


8.5 

2.2 

1.1415 

11.0 

1.5 

. 6009 


11.0 

1.6 

.6410 

14.0 

1. 85 

.5823 


11. 0 

1. 55 

. 6209 

8.5 

1.25 

.6480 


8. 3 

1. 15 

.6106 

15.0 

0. 75 

. 2203 


12.0 

0. 55 

.2019 

2.0 

0.2 

.4406 


4.5 

0.5 

. 4896 

23.0 

0.6 

.1149 


6.0 

0.8 

.5875 

9.0 

1.0 

. 4896 


10.5 

0.8 

.3357 

9.0 

0.9 

.4406 


8.5 

1.2 

. 6221 

10. 5 

1.7 

.7134 


11.7 

1.5 

.5649 

7.0 

1. 6 

1. 0072 


16.0 

1.5 

.4131 

9.5 

1.5 

.6957 












11.0 

1.33 

.5328 


9.0 

0. 83 

. 4064 

8.3 

1.0 

. 5309 


9.0 

1.5 

.7344 

13.5 

1.9 

. 6202 


7.0 

1.4 

. 8813 

6.5 

1.0 

.6779 


10.0 

0.8 

. 3525 

6.0 

0.4 

.2937 


14.0 

0.6 

.1888 

3.5 

0.4 

. 5036 
















7.0 

0.7 

.4406 

11.0 

0. 95 

.3805 




15. 6090 



14. 4231 




0. 6244 



0. 5547 









Mean of 76 ebbs. 0.6834 

Mean of 76 floods.5897 

Highest velocity ebb-tide, December 13. 1.1751 

Highest velocity flood-tide, December 13.... 1. 0649 












































































































52 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Lowest velocity ebb-tide, February 26. 1888 

Lowest velocity flood-tide, February 14.1149 

Mean of 76 ebbs.... 0. 6834 

Mean of highest and lowest ebbs.6819 

Mean of 76 floods. 0. 5897 

Mean of highest and lowest floods.5899 


Approximate area of cross-section of proposed jettee, 70,000 square feet. 536,000 — 


70,000 = 466,000 square feet, are of a diminished cross-section. 
Substituting this value, the formula becomes : 


V ~ 466000 X 3600 X t 

Substituting the values of h and t on the dates of highest and lowest velocities, both 
flood and ebb tides, we have: 

Highest velocity, December 13, ebb-tide. 1.1751 

Same, with diminished cross-section. 1. 3516 


Increase...1765 

Highest velocity, December 13, flood-tide. 1. 0646 

Same, with diminished cross-section.;. 1.2249 


Increase.] 600 

Lowest velocity, February 26, ebb-tide. 0.1888 

Same, with diminished cross-section.2172 


Increase.*..0284 

Lowest volocity, February 14, flood-tide.. 0.1149 

Same, with diminished cross-section.1322 


Increase...0173 

Mean of increase—floods. 0. 088® 

Mean of increase—ebbs_ * .. 0.1024 


B. 

Memoir of the Delta Canal, from the Mississippi River, below Saint Philip, 
into the Gulf of Mexico, near Isle au Breton / compiled from the best 
sources, by William M. Bumvell. _ f 

The immense resource of agricultural and other productions in the 
Valley of the Mississippi, above the capacity of the Southern States to 
consume, has imposed upon the farmers, merchants, and statesmen of 
the West the indispensable need of a free outlet to all the markets of 
the world by way of the Mississippi. 

The admitted obligation of the Federal Government to construct this. 
outlet devolves upon it the duty of devising the plan, providing the 
means, and executing the work. We hold the Government to the 
responsibility, and are not willing to accept the substitution of any 
individual or corporation. 

Various modes of deepening the outlet passes have been proposed 
and tried. Their advocates insist that the experiments have not been 
made under favorable circumstances, and some demand a repetition. 
The leading plans proposed and subjected to more or less experiments 
are— 

Dredging, dredging out, and carrying away the bar across the chan¬ 
nel. 





























IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 53 

o c 11 lent wing-dams, caissons, and by closing all 
tlie passes except the channel pass. 

Lighterage by pontons or camels. 

Canalization across the land from deep water in the river to deep 
water in the Golf. 

We will, therefore, state the various attempts made to remove the bar 
upon each of the theories cited. 

I. By dredging .—In 1839, Captain Talcott, under instructions of the 

ar Department, attempted to open the Southwest Pass with the ordi¬ 
nary bucket-drag. No permanent improvement was effected, for during 
a single night of storm “twice as much mud” was driven by the Gulf 
waves into the pass as he had taken away. A tow-boat association, 
under the direction and at the expense of the Federal Government, at¬ 
tempted to open the same pass. They used the rake and harrow, and 
after working a year they opened a channel of 18 feet in depth for a dis¬ 
tance of about 8,000 feet. This remained open a short time, and was 
prematurely and permanently closed by a single Gulf storm. 

In the years 1868-’69-’70, the Government caused to be constructed, 
at a cost of $350,000, a steam-propeller dredge, with all the appliances 
which science could suggest or experience justify; she was commanded 
by competent and disinterested officers of the Federal Navy; these men 
performed their duty faithfully. The dredge-boat was repaired and 
altered without regard to expense, and the experiment of dredging has 
been conclusively made. It lias failed to maintain, permanently, a much 
greater depth of water than that which nature lias prescribed as the 
regimen depth of the bar.* Dredging has, therefore, proved a failure. 
To deepen the bar at the season when there is little current-deposit, is 
not very difficult. The whole labors of a season have been, and may 
be again, destroyed in a night. 

II. By concentration of current .—The theory of Mr. Long has been 
stated by him to consist in concentration of current by closing all the 
passes except those destined for navigation. In 1830, Messrs. Oraig & 
Lighter entered into a contract with the Government to open two chan¬ 
nels 1,000 feet by 18, in a straight line via Southwest Pass and Pass 
a Loutre, respectively. They built a break-water by driving strong piles 
faced, 1 feet apart, connected by 4-inch plank. This dike was built 3,000 
feet in the Southwest Pass, and 550 feet in Pass a Loutre. As this con¬ 
tract was not renewed or continued, we may infer that the Government 
was convinced that concentrating the current of the Mississippi by plank 
walls was not feasible. The experiment of deepening the channel by 
blasting with gunpowder was then tried, we believe, by the same con¬ 
tractors. It was for a time partially successful, but another storm proved 
that nature can replace mud under 20 feet of water much faster than 
man can move it away. The aggregate cost of these experiments has 
been estimated at more than $2,000,000. 

III. Lighterage .—The cost and difficulty of this mode of transportation 
have never justified its adoption. 

Canalization .—No experiment beyond the surveys and estimates here¬ 
tofore referred to has been made to test the success of a canal outlet. 
There are two projects before the public, proposing to connect the Mis¬ 
sissippi with Lake Pontchartrain and Lake Borgne. The latter ap¬ 
proaches completion, and will furnish an excellent mode of conducting 
the inboard and coastwise navigation along the numerous lakes and 
bayous with which the Gulf coast is connected. As neither of these 

* See report of officers in charge of the dredging, stating the injury done to their im 
proved channel by the stormy weather, about 1st September, 1871. 



54 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


side-cut canals can carry into the Gulf the maximum depth of water 
demanded by the great crops of the West, they cauuot be accepted, 
even if successful, as a solution of the great questions of commerce in¬ 
volved. 

Even did these canals offer an adequate outlet, they will have been 
constructed under corporate authority, and subject to a toll on the ton¬ 
nage which may pass through them. The cities of New Orleans, 
Saint Louis, Cincinnati, and Louisville, all engaged in relieving the 
charges in river navigation, will accept nothing less than a free and 
adequate outlet to the ocean. They require that all obstructions, from 
the cities of Pittsburgh and Saint Paul, respectively, to the Balize, 
shall be relieved by free canals, constituting a part of the national high¬ 
way. 


HISTORY OF THE FORT OF SAINT PHILIP CANAL. 

Some time previous to the year 1832, Mr. Benjamin Buisson, then the 
State engineer of Louisiana, suggested the idea of avoiding the bars of 
the Mississippi by a canal from Fort Saint Philip to a deep-water point 
in the Gulf, off the island of Breton. He made a reconnaissance of the 
intermediate ground, and based his works of construction into the 
Gulf upon the hydrography furnished by the best existing charts. 
From these he deemed the plan feasible, and so far impressed his views 
upon the legislature of Louisaua as to induce, in February, 1832, the 
adoption of the resolution which follows: 

It appearing from a chart executed by Mr. B. Buisson, of the coast adjacent to and em 
bracing the mouth of the Mississippi, that a canal six and a half miles long, commeuc 
ing on the left bank of the river, a few miles below Fort Saint Philip, and entering th° 
sea about four miles south of Le Breton Island, would afford an easy and safe access t° 
the river to vessels drawing 20 feet; and being strongly impressed with the importanc 6 
of an improvement thus brought into notice by the ability and public spirit of an in" 
dividual, and believing that it would be of a great and incalculable advantage to the 
nation at large: It is therefore 

Resolved by the senate and house of representatives of the State of Louisiana in general 
assembly convened , That our Senators and Representatives in Congress be requested to 
bring to the notice of the General Government the probable practicability of such a 
work, and to urge an early estimate and survey of the same by competent officers. 

These resolutions were presented to Congress, accompanied by a me¬ 
morial of the chamber of commerce of New Orleans, and so far met 
approval that a survey was ordered, which was reported from the War 
Department iu 1837. From the document thus communicated we ex¬ 
tract the following : U L. Poole, United States engineer, says he sounded 
down Pass h Loutre, and along the coast of Breton Island, and also 
for several miles above and below Cape Point Au Sable. The deepest 
water found was near Cape Sable.” He adds: 

I come now to the project of an artificial cut from the river to the Gulf. I found near 
Point au Sable, opposite Breton Island, four fathoms (24 feet) water within ihree-quar- 
ters of a mile of the shore, which is a low sand-bank, apparently unchanging, affording 
an indication that the sand off this coast is not loose and floating, but hard and firm. 
About half the distance from the shore to deep water the bottom is hard sand, and, ex¬ 
cepting a short distance at its outermost extremity, the remaining half is hard mud, 
forming a hard foundation for heavy walls. 

The distance from the Gulf shore at this point to the river, as ascertained by the im¬ 
perfect means I had for the purpose, is about seven miles^ over a marsh intersected by nu¬ 
merous bayous,* which cover a large portion of the intervening space, but are everywhere 
very shoal, and presents no important obstacles to the projected work. 

An accurate survey of the coast from Passi\ Loutre to a point ten or twelve miles above 

* This coincides with the same sounding reported by Gould, a century before, who 
reports a bottom along that part of the coast of sand and sand with shells. 




IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 55 


Point au Sable, including the corresponding point of the river, and minute examination 
of the character of the soil to the depth which it is to give the canal, will be necessary 
to determine the best possible location, as well as to establish the certainty of the feasi¬ 
bility of the project. It is my opinion that it offers a fairer prospect of certain results 
than any other plan that has been spoken of, of opening the Mississippi to ships of the largest 
class. A lock at the junction with the river will prevent the deposit of mud in the 
canal, and the jettees at the sea may be so placed as to form a perfect artificial bastion. 

State Engineer George W. Long, esq., is of the opinion that u dredg¬ 
ing out either of the passes would be an ineffectual operation to im¬ 
prove them, for if they could once be cleared out they would soon till 
up again.” He u does not know how you would succeed with your 
canal; if you could make it with a lock, you would find it a difficult 
thing to secure a foundation, and without one it would be doubtful 
whether the banks will stand or not, and on the north side of the Mis¬ 
sissippi River there is too much floating sand for a convenient opening 
of the canal into the Gulf.” He thinks that “ the navigation of the 
Mississippi may be improved by obstructing the smaller mouths with 
heavy booms, well anchored across them, to retain the drift-sand to be 
conducted into them for the formation of rafts, to break the current and 
allow the deposit of the sediment to fill up the channels, and thus ulti¬ 
mately to close up all but a single pass. 

Mr. Fred Wilkinson, deputy surveyor-general of Louisiana, “ appre¬ 
hends heavy back-water from any attempt to block up any of the 
auxiliary mouths of our great rivers.” He says: 

The project of a ship-canal near and a little to the eastward of the Pass Loutre is 
certainly, from what I have heard from persons acquainted with the subject, a feasible 
matter; and from the depth of water stated now to exist in the Gulf of Mexico, into 
which the canal is to open, (34 feet,) is highly recommendable. The only objection 
that strikes me is the enormous expense of the attempt, from having to pass through 
the description of country at the mouth of the Mississippi. 

The excavation of the earth consists in throwing out liquid mud, and, from the dis- 
agreeableuess of the situation, every labor requisite will cost, of course, in proportion. 
A ship-canal of only a few miles in length can (including the cost of guard-locks, sets of 
which, built in the most perfect manner, will be required, both on the ocean and the 
river) be only reckoned by millions. In case of the ship-canal being resolved on, I have 
no doubt, judging merely from what I have been informed, and not from actual survey, 
that the neighborhood of Pass it Loutre is, from its being partly land-locked and shel¬ 
tered from our prevailing winds, a most eligible location for the same. It is difficult to 
give a decided opinion without narrow personal inspection of the held of observation, 
but I presume that building guard-boats, a breakwater, and artificial harbor will be 
requisite in case of the ship-canal being determined on by the Government. 

Of this canal improvement Mr. Wilkinson subsequently says that it 
is, in his opinion, u perfectly practicable,” subject only to the objection 
stated. 

Capt. A. H. Bowman, United States Engineers, reports that, in his 
opinion, “the only practical plan for securing a permanent ship-chan¬ 
nel for vessels of the first class to New Orleans is to cut a canal from 
some point on the Mississippi above its mouth to some one of the arms 
of the Gulf which approaches nearest the river.” 

The three last opinions are not vouched for on actual survey by the 
officers themselves. The most authentic document, based upon and em¬ 
bodying all that had been demonstrated upon the subject to the date 
of 1837, was the report of Capt. W. H. Chase, of the United States En¬ 
gineers, predicated upon “a partial survey of the mouths of the Missis¬ 
sippi River and of the line indicated by Major Buissou, State engineer 
of Louisiana, for a ship-canal, all having in view the improvement of 
the navigation of the said river.* 

* Report of survey of Mississippi River, 24th Coug., 2d session, Doc. No 173, House 
Rep.; executor, signed C. Gratiot, Chief Engineer United States,24th February, 1830. 




56 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Captain Chase says: “The obstacles presented to the easy entrance 
of the Mississippi by vessels drawing 12 feet ol water are productive of 
great injury to the commerce of New Orleans, and require to be prompt¬ 
ly removed, or, failing to be done, the construction ot a skip-canal on 
the plan indicated by Major Buisson should be resorted to.” 

“By reference to Chart No. 1 the line of the proposed canal is ex¬ 
hibited, commencing at a point about two and a half miles below Fort 
Jackson, and extending seven miles to the shores of the Gulf, and thence 
by a jettee 1,700 yards to 30 feet water. It is proposed to carry into 
effect this plan of a ship canal.” 

I. By a construction of a guard lock at the junction of the canal with 
the river. The object is to prevent the ffowing of the river into the 
canal. 

II. The excavation of the trunk of the canal 100 feet wide at top, 30 
feet wide at bottom, and 30 feet deep. The object of such large dimen¬ 
sions is at once to provide not only for the entrance of the largest ships 
engaged in commerce, but also for ships of war of the largest class. The 
advantages offering for both classes are obvious and need no comment. 

III. The construction of thejettees or breakwaters of large dimen¬ 
sions, having for their base 100 feet, with a depth varying from 5 to 30 
feet, and 20 feet wide at top, and raised to the level of high water. 

“The practicability of this plan depends solely on the question whether 
a lock of the dimensions requieed for the admission of the largest-sized 
vessels can be constructed on the banks of the Mississippi. I think the 
question may be easily answered in the affirmative, for we can to the 
practicability of excavating almost to any depth in the mud of the Mis¬ 
sissippi delta, as exhibited at the several works constructed by the 
United States, and by individual enterprise. At Fort Jackson, on the 
Mississippi River, the foundations were excavated to the depth of 12 feet, 
and were kept free from water by means of a small engine attached to 
pumps of considerable power. The operations at Fort Jackson came 
frequently under my observation, aud I left in no doubt as to the perfect 
practicability of excavating to the depth of 30 feet, and also of the 
practicability of establishing a solid foundation by piling, for the sup¬ 
port of the walls of masonry necessary for the construction of a lock. 

“ Taken for granted, therefore, that a lock can be constructed, we have 
only to consider the means of excavating the trunk of the canal and the 
construction of a shore breakwater. The marsh lying between the river 
and the Gulf, through which the line of the canal is located, is inter¬ 
sected by bayous, all of shallow depth of water. Commencing at the 
river, it is proposed to excavate to a depth of 6 feet, affording sufficient 
water for the dredging-machine, which will thereafter be employed in 
the excavations, the canal being excavated to a depth of 6 feet through 
its extent. 

ESTIMATED COST OF CANAL. 

Lock ‘200 by 50 by 20, the excavation including pumping 24,000, at $1.50_ $36,000 

1,000 piles, 30 feet long for tlie foundation of works, and floor of lock drawn 


close together at the bottom excavation, at $8. 8,000 

6,000 yards cubic stone masonry in hydraulic, at $15. 90,000 

Cut-stone work for coping, gates, &c. 6,000 

Gates and guard-work on river. 20, 000 

Superintendence, contingencies, including funds for the engineer to adopt 
any other improvement that may suggest itself during the construction, 

say. 140,000 

In the trunk of canal the following dimensions will be required : 100 feet 
at top, 30 at base, 36,960 feet in length, 2,665,333 cubic yards excavated 
by steam dredging machinery, will not require the use of pumps, and 
may be performed for $1 per cubic yard, including cost of machinery and 
every expense. 2, 665, 333 








IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 57 


FOR JETTEES OR BREAKWATERS. 

Each jettee will require the following dimensions : 100 by 20, depth 5 to 
HO feet, 5,280 feet in length, equal to 205,333 cubic yards for one jettee, 


for two 410,666—$6 per cubic yard. $2,363,996 

Channel between jettees, excluding from mouth of canal on the Gulf shore 
to the entrance of the jettee, 1,000 feet in width ; depth 17^ ; 5,280 long; 

3,420,000 cubic yards excavation by steam dredges under protection of 

jettees, at $1.. .. 3,420, 000 


RECAPITULATION. 


For trade and guard-works. $300, 000 

Trunk of canal. 2,665,333 

Jettees of breakwaters. 2, 333, 966 

Channel of jettees... 3, 420, 000 

Total. 8,619,299 

This estimate, swelled to 810,000,000 by the caution of this eminent 
engineer, was at that date a preposterous sum to be applied to any 
public improvement. The West did not possess the power to pass the 
appropriation, and the South in its hostility to all such appropriations 
was divided in its support. 

Twenty years later, Mr. R. Montaign, a civil engineer, revived the 
idea. * He based his studies upon the data furnished by Buisson and 
Chase, and adding thereto a personal examination, which continued for 
more than six months, produced a plan for constructing the canal by 
private subscription. In a remarkably able and exhaustive essay he 
demonstrated that the work was practicable; that its cost would not 
exceed one-third of the Federal estimate, and that, taking the actual 
commerce of the river-outlet in 1859-’G0, the interest account and ex¬ 
pense of maintaining the work, deducted from the receipts, would leave 
a net profit of 25 per cent, per annum upon the investment. This plan 
was indorsed by the merchants and other capitalists of New Orleans, 
and received the approval of the chamber of commerce, the insurance 
companies, and the press. The war and the death of the projector de¬ 
feated this proposal, but, with the restoration of peace, the project of a 
national canal, as recommended by the legislature of Louisiana, was 
brought forward, under the auspices of some of the oldest and most 
eminent merchants. A committee of the chamber of commerce was 
appointed, which renewed the recommendation of the work, and pressed 
its adoption upon the Government. In the mean time mechanical skill 
has greatly reduced t he cost of alluvial excavation, and experiment is 
demonstrating the entire feasibility of the plan proposed. Dredging- 
machines will do the work, at something like one-fourth the cost of 
manual labor. Within sixty miles, by water, of the site proposed for 
this Delta canal, another, connecting the river with Lake Borgue, not 
only demonstrates, experimentally, all questions of construction raised 
by the earlier commissions, but will in a few months, at the close of its 
contract, have at its disposal, identically, the dredging machinery re¬ 
quired for the purpose. A recent letter, addressed to the writer by M. 
J. Thomson, esq., civil engineer in the service of the State of Louisiana, 
offers an estimate of the cost of constructing a ship-canal on the ground 
proposed, of the dimension of 300 feet on the top, 200 feet at the bot¬ 
tom, and 2G feet in depth. After making a careful calculation of the 
cubic earth work, which he estimates at 1,271,111 cubic yards per mile, 
this engineer places the cost of the canal at $500,000 per mile. For 
the guard-locks he considers $500,000 sufficient; and allowing even a 
million for the piers, would place the whole cost at about $5,000,000. 












58 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


This estimate might be reduced somewhat, in the opinion of other en¬ 
gineers, who regard the cost of earth-work at less than is estimated. 
Five millions is, however, a liberal if not an excessive allowance, and 
yet how insignificant, in view of the obligation to be discharged and the 
interests to be developed. 

In addition to the example of canalizing the Delta for a connection 
with Lake Borgne, we are furnished with a far higher and more decisive 
model of national emulation. Modern science and capital have renewed 
the works of the Pharaohs, and completed a canal from the Mediterranean 
to the Red Sea. This work opens with a deep-water harbor of 400 acres, 
protected by piers of artificial stone. It is embanked forty miles through 
the lakes Menzaleh and Ballah, through the high lands El Guisr, with 
a cutting of 85 feet; then into Lake Timsah, where an artificial port 
has been constructed; then through the deep cuttings of 62 feet at 
Toussoum and Serapeum; then, at a distance often miles, entering the 
Bitter Lakes, and passing a distance of twenty miles through a channel 
marked by light-houses and buoys; thence through the deep cutting of 
56 feet at Ohalouf, through sands and a marsh, a distance of twelve miles 
to Suez, where it ends in another artificial harbor. The length of this 
canal is one hundred miles; its greatest surface is 328 feet; the least 
bottom width 72 feet; the depth is 22 feet, which is being increased to 
26 feet. This work has been constructed through the alluvion of the 
Nile and the lakes, through volcanic rock, and through the drifting 
sands of the desert. The power of obstruction of these last may be 
inferred from the fact, that between Lake Timsah and Port Said, a dis¬ 
tance of fifty miles, it is estimated that 1,300,000 cubic yards of sand 
will be swept into the canal annually. “This will give employment, to 
one of the largest dredges for three or four months, working twelve hours 
each day.” In the year 1869, 1,362 ships, of 672,000 tons, entered the 
canal, and this tonnage has been rapidly increasing. 

Here, then, we have a work far more extensive than the proposed 
canal of the Delta. It passes through similar, and also through more 
formidable formations. It is embanked through lakes, and opens into 
capacious artificial harbors, formed with artificial stone. It is subject 
to an obstacle analogous to the sediment of the Mississippi—the drifting 
sands of the desert. 

We will now exhibit the items of— 

COST OF THE SUEZ CANAL. 


Preliminary surveys from 1854 to 1857. $15, 825, 525 

Administration and negotiations. 3, 394, 245 

Sanitary service for 1866 to 1869. 121, 410 

Telegraphic service.... 34, 000 

Transportation, boats, buildings, &c. 1,644,435 

To contractors, for materials. 2, 442,785 

Dredging-machines. 6, 819, 240 

Workshops. 844,150 

Works of construction, canal, &c. 43,534, 330 

Miscellaneous. 1, 392, 493 

Various branches of management... 3, 843,050 

Balance to deepen canal to 26 feet. 9, 437, 560 


Total. 90,331,223 


This gives us an average of $806,936 per mile as the cost of this 
canal, with its two ports, estimated at more than half the amount ex¬ 
pended for excavation. In conceding this calculation to be correct, we 
feel authorized to strike out certain items as inapplicable to the Forr. 
















IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 59 


Saint Philip Canal. The general expense of administration of the Suez 
Canal, and the diplomatic negotiations, are excessive and unnecessary. 
There are other items which would not cost the United States as much 
as the corporation of Suez; the expense of preliminary surveys and 
superintendence would be much less. The delivery ot supplies on the 
banks ot the Mississippi and the G-ulf coast would be cheaper than upon 
the shores of the Mediterranean. A pioneer ditch, as on the Mobile 
and I ex as Railroad, would deliver the materials of construction along 
the whole line ot canal without the necessity of employing’ draught-aui- 
mals for that purpose. The completion of the levee reparations and 
the approaching completion of the Lake Borgne Canal will place at the 
call of the Government a large amount of labor, skilled in, and inured 
to, alluvial excavation, with a number of improved dredging-machines, 
now employed in performing exactly the kind of work required on the 
ship-canal. 

ARGUMENT. 

The capacity of the soundings off the shore of the Gulf of Mexico, 
and through that channel to the sea, is shown to be ample for the pas¬ 
sage ot any commerce. These soundings are unchanging. A century 
ago the British government ascertained and published a chart, which 
has been verified by subsequent surveys of the United States, and 
found to be the same. Congress has ordered a survey and reconnais¬ 
sance of the work, with estimates of probable cost. They will be made 
during the ensuing fall and winter by the intelligent officer at present 
in charge of the Essayons, Capt. C. W. Howell, United States Engineers. 
This, then, offers an ample and permanent passage and anchorage at the 
canal outlet. The depth of the liver is sufficient at the inlet for all 
possible purposes. An adequate and undoubted depth of water for the 
inlet and outlet between the river and the sea is then established—not 
on conjecture, but upon fact. The first term of a deep-water outlet 
established, it becomes a proposition of expenditure and science to 
effect it. 

THE FINANCIAL QUESTION. 

It is not our purpose to review the mechanical, financial, or scientific 
estimates of the engineer. The duty of the Government and the public 
necessity for a great work having been established, the details of execu¬ 
tion rest with the proper authorities. > 

With the immense domain aud incalculable values locked up within 
this Mississippi Valley, it would seem a matter of small moment what 
portions of those values shall be devoted to their development. It may 
be added, moreover, that when the Government has already expended 
several millions for the canal around the Des Moines Rapids, and nearly 
as much more in making the canal around the falls of the Ohio, it 
would be poor economy to refuse the canal from the Mississippi to the 
Gulf. This will complete the system of artificial relief to the whole 
navigable length of the Mississippi and Ohio Rivers. Without the 
Delta Canal to give outlet to the developed products of the West, the 
enlarged capacity of the upper rivers must fail of its full effect. 

But the Government, in acknowledging the obligations to keep open 
these outlets, will naturally seek the least expensive and most certain 
way of doing so. That mode which insures a vast commerce against 
obstructions is most economical. Cost what it may, the Government 
cannot afford to dispense with it. The annual cost of repairing and re¬ 
placing the vessels employed may be safely set down at $250,000. If 


60 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


we assume the cost of the Fort Saint Philip Canal as stated in thispaper, 
say five millions, the Federal Government need only emit that amount 
of bonds bearing live per cent, interest, and the amount oi interest 
would be but little more than the present cost. The complete execution 
of the whole work would save much trouble in organizing an annual ex¬ 
pedition against the obstructions, when valuable lives are risked in 
unequal combat with the elements and the epidemics. 

The dredge-boat Essayons has been obliged to interrupt her work dur¬ 
ing the summer of 1870 from this last cause. There is, however, another 
reason why those who are especially interested in the outlet navigation 
should desire this permanent improvement. With the most sincere de¬ 
sire for the preservation of peace, foreign and domestic, with the utmost 
faith in the disposition of the American people to keep every obliga¬ 
tion, we cannot expect to be always exempt from political disturbances 
which have affected all nations at all times. If the annual appropriation 
for dredging the outlet should fail or be suspended from any of those 
legislative accidents so familiar to all, nature nevertheless brings her 
alluvial tribute and lays it upon the threshold of the ocean, and the 
people and products of the West are barred of their passage to the 
world markets. Commerce is suffocated. Who can compute the loss, 
the discontent, or the disappointment? If, however, the Government 
shall apply a capital amount of bonds, the interest on which will be not 
much more than the present outlay, to open the Delta Ship-Canal in free 
outlet to the ocean, no accident or misfortune, no political mishap or 
defeat can deprive the Great West of a permanent, perpetual, and per¬ 
fect way of communication with the world. It has been remarked by a 
sagacious American, of the canal across Suez, u But whether the canal 
company be a success or a failure to those who have thus far invested 
their money in it, is of little moment in the world’s history. The new 
route is there; it will remain, aud if one set of persons cannot make it 
pay, then it will fall into the hands of others. 7 ’ This has been already 
verified. 

The Fort Saint Philip Canal would thus effect an ultimate economy 
in the annual expenditure of the Government; for it would encourage 
greatly the importation of dutiable goods in exchange for the developed 
products of a country otherwise inaccessible to agricultural industry. 
The West will have a permanent and adequate outlet to the sea, and 
will receive a large part of the national expenditure, and of its own 
-contributions for that purpose. It must not be forgotten that as the 
American empire spreads along the slopes of the Rocky Mountains it 
must pass a point at which the exportation by rail of the cereal crops 
grown on the parallel of our chief Atlantic cities must become unprofit¬ 
able. This will be obvious from a single example : The average quantity 
of wheat grown on an acre in Massachusetts is 18 bushels, worth $1.75 
per bushel. The average cash value of an acre grown in wheat is $81.56. 
The average quantity of wheat grown upon an acre in Minnesota is 
10 3-10 bushels, and the average cash value of an acre of wheat is 
$9.61. This would make a bushel of wheat grown in Minnesota worth, 
to the farmer, less than sixty cents. When we deduct from this price 
the cost per bushel of moving the wheat from the Minnesota farm to 
the depot, there can be little inducement to its culture, nor can it be 
carried much farther back, unless some cheaper mode of transportation 
be provided. We have taken these statistics of production and value 
from the annual report of the Agricultural Bureau. The same report 
supplies an appropriate comment in saying : “ The continuous planting 
of new lands of the West with wheat is running west, year by year, 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 61 


the culture of wheat production, and increasing the distance of trans¬ 
portation, while the railroads, by their combination and advance of tolls 
to secure dividends upon watered stock, are increasing in equal ratio 
the cost of freights.” The quantity of edible grains from west of the 
Mississippi—including, also, the product of Wisconsin—is about two 
hundred and fifty millions of bushels. Now, the extent to which the 
freights upon this product can be reduced, the inducement to emigrants 
to go upon the immense area of unoccupied Territories of the republic, 
will be increased. The experience, however, of all ports from which 
grain is exported, shows that vessels of very large burden, of great 
draught, and of peculiar build are required to conduct this trade with 
economy. The largest class of vessels trading from Chicago over the 
Saint Clair fiats are of about 2,500 tons, and of 12 feet draught. The 
Welland Canal only allows the passage to sea of ships of about 000 
tons, drawing 12 feet. These figures allow the exportation of cargoes 
of about forty thousand bushels of grain through the lake outlets As 
the increase of draught and tonnage in the vessel diminishes the cost of 
transportation per bushel, it leaves to the farmer so much more of the 
price of his wheat in the ultimate market. 


WARNING TO THE WEST. 


The immense additions to the wealth and numbers of the Upper North¬ 
west, the opening of the Saint Lawrence River and the Canadian canals 
in free passage to American commerce, and the rapid development of 
trade and immigration by that route, point to the rapid organization 
of a new sectional interest, to be based upon lines of railroad crossing 
the continent to British Columbia and Puget/s Sound, by way of the 
Red River of the North. The Hon. W. Kelly, in a recent address on 
the u New Northwest,” describes the country intervening between Lake 
Superior and the Pacific to be fertile and of a mild climate. He expressed 
confidently the opinion that there will be a column of States carried 
across the continent, but predicts that the largest city on the Pacific 
coast will be at Puget Sound, because of its abundant food, fuel, 
and its moderate temperature. The tendencies are toward an admission 
of the Canadas, with a population of four and a half millions, into the 
Union. With the present political power along the frontier States of 
the Northwest interested in the Canadian and other routes to Europe, 
and with the fact that the exports were 23,000,000 bushels of wheat 
last year by the Saint Lawrence, an increase of seventy per cent, within 
three years past, the present West should see the power and the 
motive to erect the Saint Lawrence route into a rival of the Mississippi. 
What means so simple to enhance the advantages of the eastern routes 
as by employing the vote or the veto to suspend the annuity for dredging 
the mouth of the Mississippi? Regard the trade and travel between 
the West and the tropical countries. See Baltimore, New York, and 
Boston competing to supply western products in exchange for coffee, 
sugar, and other commodities. Is there not reason why the \\ est and 
Southwest should apprehend Indifference, if not opposition, to the di¬ 
rect outlet of the valley ? And let it never be forgotten, that with even 
the cessation of a single season, all the work must be repeated.* 
The West will not have the power to protect itself forever. Under the 


* The normal depth of the river will always return. Daniel Coxe, in a work upon the 
English and French colonies, published in 1727, says: “ The-Mississippi River has seven 
mouths, with a depth of fourteen teet on the bar.” 





62 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

present census let its merchants, manufacturers, farmers, and statesmen 
demand that this natural and indispensable outlet shall be placed on 
such a footing as that no future inaction or opposition can impair its 
usefulness. 

Why, then, should not Saint Louis, Cincinnati, Louisville, and the whole 
country that they represent, demand at once the permanent opening of 
the Mississippi outlet by a canal which can never be closed or taken away ? 

It will be said that the present mode of improvement by dredging 
is successful. We take pleasure in stating that the latest report of 
the officer in charge of that work shows a good broad channel worked 
out by the dredge to the depth of eighteen feet.* Vessels can now be 
safely consigned to New Orleans without fear of being stranded on mud- 
lumps. To the dredge-boat now at work on the pass and bars will be 
added, in January next, a consort. This will insure adequate naviga¬ 
tion. We hail this as a temporary measure$ it will keep the commerce 
until a more permanent shall have been executed. It is in fact a scaf¬ 
folding for the erection of the Fort Saint Philip Canal. We have given 
the reasons why that work should be preferred to any substitute. 

The navigation of the Mississippi cannot be materially enlarged with¬ 
out providing for the reduction of freights. 

This cannot be effectually done without enlarging the capacity of the 
vessels carrying grain to a transatlantic market, and this involves the 
necessity of opening an outlet channel adequate to carry the large car¬ 
goes essential to cheap freights. The Des Moines Kapids Canal and 
the Fort Saint Philip Canal are, therefore, works necessary to the de¬ 
velopment of the public domain west of the Mississippi. They are as 
much auxiliary agents of further sale and settlement as the railroads 
based upon public subsidies which traverse it. We will, however, take 
a more enlarged view of the necessity for this 

OUTLET OF AN EMPIRE. 

The surface drained by the Mississippi exceeds 750,000 square miles, 
without regarding the fact that the column of States on the eastern 
slope, in the gorges of the Rocky Mountains, will be compelled to draw 
their tropical commerce through the Mississippi outlet. The population 
of this area numbers little less than 17,000,000, upon an average of 
about 20 to the square mile of the settled portion, a density capable of 
almost indefinite expansion. To the normal rate of natural increase 
may be added a large accession of foreign immigrants. This region 
exhibited in I8G9 the following statement of 


FOOD PRODUCTION. 


Indian corn 
Wheat .... 

%e. 

Oats. 

Barley. 

Buckwheat 
Potatoes ... 


Bushels. 
650,000, 000 
180,000, 000 
4,000,000 
170,000,000 
♦, 000 , 000 
5,000,000 
40, 000,000 


Total 


1,063,000,000 


* Channel changed by stormy weather, September, 1871. 













IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 63 


OF ANIMAL FOOD. 


There was received in 1809, at— 

. Beef-cattle. 

Chicago. 403, 502 

Saint Louis. 222,000 

Cincinnati, (estimated). 150,000 

Louisville, (estimated). 75, 000 

New Orleans, (estimated) . 100,000 

New York from Western States. 186,000 


Total. 1,136,502 

Hogs packed in tlio western cities, 1869-70, (estimated) . 4, 000, 000 


This immense product, it must be remembered, is the surplus of live 
stock held in the country. These are computations of the leading ar¬ 
ticles of. production. They omit wholly the manufactures, whose value 
may be inferred from the annual productions of the four chief cities of 
the valley— 


Saint Louis. $150, 000, 000 

Cincinnati. 125,000, 000 

Chicago, (estimated)... 100, 000, 000 

Louisville, (estimated)-. 75, 000, 000 


Total.. 450,000,000 

The immense provision product will be combined with the coal, iron, 
lead, copper, salt, lumber, cotton, and innumerable other commodities 
which are or may be developed, so that if the export of provisions shall 
decline, their value will be more than made good in the exportable com¬ 
modities into which they will have been transformed. Oontining our¬ 
selves, however, to ascertained products which require an improved out¬ 
let to the ocean, we offer the estimate which follows : 


TOTAL TONS EXPORTED AND EXPORTABLE FROM THE MISSISSIPPI VALLEY. 


Tons. 

Cotton... 350, 000 

Tobacco.. 36,000 

Grain. 2, 000, 000 

Other provisions. 120, 000 


Total. 2, 606, 000 


Here, then, is a probable commerce that for exceeds that of the Isth¬ 
mus of Suez at present. Will our Government hesitate to give five mil¬ 
lions, when individuals have subscribed a hundred millions for a similar 
work in a foreign land? 

These figures omit much detail of authentic statistics. They may ap¬ 
pear startling, but they are true. When we reflect that this vast area 
has only been subject to the control of intelligent man for about three- 
fourths of a century, and note its prodigious increase of wealth, popula¬ 
tion, and progress, no estimate can be excessive. When Mr. Burke, in 
his great and unavailing effort to preserve the British Union, would 
have impressed upon the nation the vast growth of the American colo¬ 
nies, he supposed it would appear to many incredible. He therefore 
said that the growth of the colonies was so that even if the estimate 
should be in advance of reality, “ while we pause to make the figures, 
the fact is upon us f a pardonable hyperbole equally applicable to colo¬ 
nies of those colonies. Our statistics grow stale even while we expose 
them to inspection. 

We ask every American legislator, is not such an empire, with such 
inhabitants and such resources, capacities, and destiny, entitled to a 























64 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


commercial connection with the outer world? Is not the standard of 
civilization iu literature and the arts in Saint Louis, Chicago, Cincin¬ 
nati, New Orleans, sufficiently high to justify these people in demanding 
facilities of commerce equal with any other portion of the republic? 
Shall a people who pay two hundred millions of annual taxes toward 
the support of the common Government be denied a highway to the sea 
at a cost of the annual interest on their contributions ? They have ceded 
to the National Government the right of taxation upon imports, the 
natural fund for removing physical obstructions to commerce. They 
have yielded the paramount jurisdiction over their natural highway to 
the ocean. This great highway and outlet was given them by the law 
of nature and of nations. It has been guaranteed against hostile ob¬ 
structions by the valor of the people who inhabit its shores. Shall this 
great highway, which neither foreign nor civil war could obstruct, be 
shut up by an accumulation of mud ? Shall these vast values be incar¬ 
cerated from market for the pittance necessary to relieve and deliver 
them ? For such services and for such contributions, for such right and 
undeniable right and obvious policy, is any appropriation excessive or 
unreasonable ? 


DISTRIBUTION OF THE EXPENDITURE. 


In the application of the money asked for the construction of the Delta 
Canal, every dollar may be paid to some important domestic interest. 
The workshops and ship-yards of the North and West will supply the 
engines, dredge-boats, implements, with the food, coal, and animals. 
The Southern States will furnish much manual labor. New York and 
New Orleans will conduct the financial administration. As every part 
of the Union will pay its quota of the cost, every part will participate,in 
the distribution of the expenditures. Not only will the construction of 
the work promote the interest of all, but it will add to the strength of 
the republic by removing a cause of sectional discontent. This consid¬ 
eration comprehends a value not to be computed in money; it has some¬ 
times cost millions in its consequences. 

The Federal Government should not limit its aid to the specific work 
under consideration. It should adopt a policy by which all impediments 
to the navigation of the main stream of the Mississippi will be removed. 
It is a natural highway, governed by national authority in its whole 
navigable length. This duty of the Government may be most effect¬ 
ually performed by canalizing the main branches at the Des Moines 
Kapids, the falls of the Ohio, and the Muscle Shoals of the Tennessee. 
The ship-canal at Fort Saint Philip will complete the system. 

The West should moreover impress upon the President his promise 
to revive the trade treaties with Spanish America, and insist on the 
same liberal reciprocity iu regard to their commerce with the Missis¬ 
sippi Valley as has been granted by England in regard to the Canadas. 
If the Great West is at this moment guaranteeing and guarding the 
sovereignty of Spain over Cuba, and the integrity of Mexico, Colombia, 
Venezuela, Chili, and Peru against European aggression, there should 
be some compensation in the facilities of trade with the United States. 
The same may be said in regard to an equalization of the postal sub¬ 
ventions connecting the Mississippi Valley with all the principal foreign 
ports to the south of' New Orleans, on this continent. These vital issues 
should be embodied in the platform of every western political conven¬ 
tion ; they should be insisted on by all candidates of all parties for the 
Presidency or for Congress. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 65 


^\e bring this extended memoir to a close by enumerating the meas¬ 
ures proper lor adoption by Congress in compliance with a national 
duty : 

^ 1. To require an immediate report from the proper department of the 
Government upon the practicability and probable cost of the Fort Saint 
Philip Canal. 

2. To direct the construction of such canal, if deemed expedient, by 
contract with responsible contractors. 

d. To appropriate an amount of Federal bonds which will net, in 
market, the sum necessary to construct the canal and ports. 

4. To include in the appropriation for the annual operations for im¬ 
proving the mouths of the Mississippi Rivera sum sufficient to meet the 
annual interest on the capital cost of the canal as well as for superin¬ 
tending and keeping the same in repair. 


a 


Project of a ship-canal between the Mississippi River and the Gulf of Mex¬ 
ico, by R. Montaigu , civil engineer. 

INTRODUCTION. 

Of all the elements which enter into and affect the value of commer¬ 
cial products, none has made more progress toward amelioration, during 
our time, than the question of mode and means of transportion. This 
truth needs no further proof when we remember that we have seen the 
inauguration of railroads and steam navigation. This extraordinary 
development in the means of communication was commanded by the 
first of all social necessities, that of relations and exchange. The pros¬ 
perity of a country is in proportion with the extent of its sphere of ex¬ 
pansion. The creation of a great commercial road, by land or by sea, 
causes rich and populous cities to rise from the soil, and former queens 
of commerce see life and motion lea^e them and take another direction, 
if some new road is inaugurated which overthrows the long-established 
habits of trade, and diverts them from their ports. 

No question, then, can present greater importance for the prosperity, 
and even the existence of a great commercial mart. It must tend to 
increase constantly the extent of its circulation by the creation of new 
means. It follows, therefore, naturally, that its first duty must be to 
keep in order and improve those means which it already possesses. 
Such is at present the position of New Orleans. 

Commanding the greatest of rivers, she sees the productions of the 
vastest agricultural valley that exists brought daily to her feet. These 
unique advantages, which she owes to nature alone, insure her a pros¬ 
perity unrivaled and boundless from the day she will choose to develop 
them by her industry and her activity. 

But to this nature has attached a condition. In establishing New 
Orleans as the queen and mistress of the Lower Mississippi, it has im¬ 
posed on her the duty of making the access thereto easy, sure, and con¬ 
stant. She owes the fulfillment of this condition to the whole commer¬ 
cial world, for, from the day that transportation through the mouths of 
the Mississippi River would become too burdensome and onerous, 
freights would have to take another and less direct route, and the com¬ 
merce of the Old and New Worlds would receive a fatal blow. 

H. Ex. 220-5 





G6 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


But the first consequence of this perturbation would be the complete 
ruin of New Orleans and the division of her profits among certain other 
commercial centers, possessing perhaps less natural advantages, but 
gifted with more wisdom and enterprising activity. 

Yet it is to this result we are marching rapidly, and we cannot even 
plead that we have not been warned in time. Science, men of experi¬ 
ence, seamen, and merchants, the facts themselves, have fully demon¬ 
strated, beyond the shadow of a doubt, that the Mississippi offers no 
longer to our vessels an immediate, easy, and safe access; that between 
the mighty river and the sea a wall has arisen, increasing every year; 
that while it would be indispensable, in order to reduce the costs of 
transportation, to introduce in our great cotton mart the use of ships 
of the largest tonnage, it has become necessary to construct, specially 
for the New Orleans trade, vessels of middling capacity, in order that 
they can surely cross the bars that obstruct the entrances to the river. 

In presence of such facts, and in presence of the formidable compe¬ 
tition which the North and East are making to draw to their markets 
the productions of the Upper Mississippi, we can foresee plainly the day, 
not far distant, when our great port will only be occupied by the coast¬ 
ing trade and opened to the navigation of smaller crafts; when com¬ 
merce will have taken another route; when our merchants and shippers 
will see the productions of foreign countries reaching them only through 
northern or eastern channels. Then, New Orleans will have passed 
from among the great commercial cities of the world. 

Are these dangers so imminent? This is what our deplorable indo¬ 
lence has, to this day, refused to convince. It is in vain that official 
reports, the complaints of ship-masters, the losses suffered by shippers, 
the dissatisfaction of consignees, the losses paid by underwriters, have 
clamored to our ears like so many alarm-bells. We are loath to suppose 
that the prosperity we have so long enjoyed can cease, and as long as 
ships arrive at our wharves, at whatever cost or condition, we remain 
slumbering in treacherous security. 

There is, beside, an excuse to be found in the difficulties of the ques¬ 
tion itself. The most judicious minds, who agree that something must 
be done, cannot come to any conclusion. Scientific men do not agree 
as to the origin of the evil. Practical men do not agree better as to the 
proper remedy to be applied. There is only one point on which all unite, 
that it would be necessary to undertake a struggle against nature 
itself, the result of which must be doubtful, expensive, and of short 
duration. However, it will admit that this is no reason why no action 
should be taken, and that if the question cannot be solved directly by 
open and bold measures, there may still be some other means to arrive 
at a solution. This we come to proclaim openly. 

Yes, the danger is so imminent that not one instant should be lost, 
not to repair the harm already done—that is beyond the power of man— 
but to free ourselves from its future consequences. Yes, something 
can be done ; something simple, logical, decisive. Thus to prove indis¬ 
putably that the powerful hand of nature closes the mouths of the river 
to commerce, and that, far from having the power, by any effort of 
science, to conquer this obstacle, we tend to increase it every day by 
necessities of another order, such as the consolidation and raising up of 
our levees, will be the first part of the task we have undertaken. 

To substitute to this opening which escapes us, another, wide, easy, 
practicable at all times, free from all the inconveniences of the present 
passes, and from all danger of closing itself subsequently, will be the 
second part of our task. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 67 


The double demonstration, if we prove adequate to tlie important task 
we have had the honor to be intrusted with, contains the salvation and 
future of New Orleans. 


PRESENT AND FUTURE CONDITION OF TIIE PASSES. 

It would be extremely hard to make a retrospective study of the 
former condition of the Mississippi, and the importance of the deposits 
that obstructed its bed during the early times of the colonization, or 
even until our time. Official information on this subject is completely 
wanting. The able State engineer, Mr. Luis Hebert, said in his report 
of 1850: 

We are still quarreling among ourselves to decide, by words and by arguments 
founded on conjectures, what the Mississippi was, what it is, and what it will be. Our 
knowledge of the past rests on facts, gathered here and there, partially in one year aud 
partially in another ; now by this person, then by another—incoherent facts, disjointed 
by time, localities, and circumstances. 

In presence of such declaration, the scarcity of anterior documents 
and the contradictions they contain, are no more surprising than the 
antagonism of opinions on actual facts, for in such matters certainty 
can only be based upon a long series of connected and systematical 
observations. 

Thus, on one side, one of our most distinguished hydrographers, Dr. 
Cartwright, states positively that the bars at the mouth of the Missis¬ 
sippi have not increased, as it is generally believed, but have remained 
the same since one hundred and forty years, excepting changes in the 
direction of the passes and differences of one or two feet in their depth, 
the effects of winds and tides. On the other hand, we find data in old 
works on this subject stating that, in 1722, there was 25 feet of water 
on the bars, and that this depth was reduced to 20 feet in 1767. In our 
days the depth is only 15J feet, as shown by the last soundings made 
by Engineer Hebert, and more recently by myself. 

It is certainly much to be regretted that a greater number of obser¬ 
vations cannot be gathered, which would enable us to determine and 
discuss the law that governs this gradually increasing obstruction, but 
it is, nevertheless, safe to affirm that the established natural tendency is 
a progressive diminution of the depth of water on the bars. 

Another fact resulting from an examination of the past is the con¬ 
tinual lengthening of the delta of the Mississippi in the Gulf. Compar¬ 
ing the exact soundings made by Captain Talcott, United States engi¬ 
neer, in 1838, with those made by the same gentleman in 1851 and in 
1852, we find the deposits of alluvion advance seaward at the mean rate 
of one mile in every 15 years, which represents a progress of 350 feet 
annually. 

Passing from the data found in the past to an examination of the 
present, we draw from official sources the following description of the 
Mississippi and its mouths in their actual condition : 

After running a distance of five thousand miles from the Rocky 
Mountains, with a mean inclination of seven inches per mile; after 
crossing a basin two thousand five hundred miles in width, aud present¬ 
ing a surface of one million one hundred and twenty-three thousand one 
hundred square miles, the Mississippi flows in a single and majestic chan¬ 
nel to within ten miles north of the twenty-eighth parallel, where the 
river divides itself in three branches: One, following the axis of its first 
direction, meanders until it empties into the Gulf of Mexico. It is the 
South Pass. Another inclines 35° westward. It is the Southwest 


68 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Pass. The third branch is no less than the principal channel, which 
relieved by these two large outlets, changes completely its direction. 
Coming from the northwest, it inclines eastward from the English 
Turn, making an angle of 125°, and continues in this new direction un¬ 
til another subdivision takes place, a portion of the mass of water flow¬ 
ing southward, forming at the Balize the Southeast Pass, the remainder 
continuing eastward, inclining somewhat toward the north, and form¬ 
ing the Pass a Loutre, or Northeast Pass. 

Thus, in reality, the river has four outlets to the sea, but only two 
interest commercial navigation. The South and Southeast Passes are 
already too much obstructed to be hereafter counted as regular out¬ 
lets. 

We will therefore confine ourselves to describing the Southwest Pass 
and Pass a Loutre. 

Here is what Mr. Hebert, the State engineer, says about the latter: 

The bar at Pass h Loutre has only a width of 250 yards, and the channel across the 
bar is 200 feet wide. A mass of mud in the center divides this channel in two. The most 
narrow has only a depth of 12 feet; the other is wide enough to give passage to a ship 
and two tow-boats, and has a depth of 15^ feet. The channel is nearly straight, and 
with the exception of the elevation in the center and of three others on the side, is free 
from obstructions. The bottom seems to be of the same nature as that of the other 
pass, sometimes hard and sometimes soft. The direction of the channel is such that 
ships can sail on the Mississippi from English Turn, with prevailing winds, during 
eight or nine months of the year. This would relieve them of the expeuse of towage . 

As to the Southwest Pass, it had, in March, 1858, 15J feet of water in 
the channel at mean tide. The bar is one mile wide, and the channel 
♦quite narrow and crooked. Mr. Hebert calls u the channel v that which 
has the greatest depths; for the bar is cut in all directions by holes and 
small channels. 

Such are, at this day, the two principal outlets of the greatest line of 
interior navigation in the world. We could prove this description to be 
faithful by multiplying quotations; but we deem it sufficient to warrant 
the conclusion that the Mississippi has, properly speaking, no reliable 
open outlet to the sea. Theory, as well as the experience derived from 
the many attempts made or projected, will demonstrate that the Missis¬ 
sippi can never, at any cost, have such an outlet or mouth. 

There are two opposite systems to explain the formation of the bars, 
and each of these systems is erroneous by its exclusiveness; for both 
are true to a certain extent. 

One of these systems attributes the accumulation to the deposit of 
ithe immense masses of matter carried along by the turbid current of 
the river, which is necessarily precipitated when the force of the cur¬ 
rent is destroyed by its junction with the sea. This is the old or fresh¬ 
water alluvion theory. , 

The other system denies that the river has anything to do with this 
accumulation, and explains it as altogether caused by the action of the 
sea. This is the modern theory of bottom waves. The sea continually 
tears up its shores, and, under the impulse of winds and currents, the 
fragments washed away by the waves are carried to enormous distances. 
When the waves strike against an obstacle, the speed decreasing and 
even disappearing entirely, the sea abandons all the solid parts it car¬ 
ried, and these, sinking to the bottom, form shoals and accretions. 
When the obstacle happens to be a stream, this deposit forms a bar at 
its mouth. 

In the excellent work of Linant Bey and of Mongel Bey, on the Isth¬ 
mus of Suez, we find that operation described as follows: 

The carrying power of the sea depends upon the size of the tides and the direction 
of the winds, as also of their intensity, combined with that of the currents which are 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 69 


found in all the seas. Thus while considerable masses of the matter are set in motion 
along the sea-coasts, the rivers, and particularly those of a great length, only carry to the 
sea muddy matter of so little weight that it is carried afar and deposited in the depths 
ot the sea. We have a remarkable instance in the river Nile, whose waters, at the 
period of inundation, can be distinguished, from their peculiar color, at a distance 
of more than ten leagues at sea. All the accretions and shoals up to eighteen miles of 
its mouth are muddy, while all the bars at its mouth are composed of sand. 

The obstacles at the mouth of the Kile, therefore, proceed evidently 
from the sea. To demonstrate this with still more certainty, we will 
quote the reasoning of the engineer, Bonnicean, in regard to the allu¬ 
vion in the river Mersey, in his excellent work on the navigation of tide 
rivers: 

If the accretion came in any sensible degree from the highlands, the quantities de¬ 
posited from time to time ought to be proportionate to the quantities of rain which fall 
during the same periods; for the volume of matter brought down from the highlands 
and carried by the river must be regulated in a great degree by the quantity of water 
that carried it. But it is a well-established fact that the accretions of sand to be found 
at the mouth are so much greater when the volume of water is smaller; while in high- 
water time, when the Nile contains nearly 0.008 of suspended matter, the sand-banks 
are carried off and distributed a great distance at sea. 

We have quoted at length in order to demonstrate at the same time 
all the force of this system in certain circumstances and its insufficiency 
in others, particularly in what concerns the Mississippi. 

To prove that the system of the formation of bars by the carrying of 
marine detritus is insufficient to give us satisfactory explanation of the 
difficulties which surround this vexed question, w r e have only to remark 
that the action of the Mississippi is directly opposed to that of the Kile. 
It is during the season of rains and high tides, when the river carries 
1.1153 in weight of matter in a suspended state, that the deposit on the 
bottom and upon the bars is greatest, which could be easil}’ foreseen, 
and is clearly explained bj^ the system of fresh-water alluvium. It is 
at the time when the difference between low-water and high-water marks 
is 14 feet, in the city, that the bars are most difficult to cross. 

As to the carrying away of the bars by a confluent volume of water 
at high-water mark and their scattering in the sea, it is a question far 
from being raised. 

On the other hand, it is evident that if the accretion of alluvion was 
caused exclusively by the Mississippi, it would take place from outside 
to inside the bar, add would tend to extend against the current of the 
stream, instead of advancing progressively seaward; as, approaching 
the bar already existing, the current would lose its swiftness and would 
allow its muddy load to settle inside of the obstacle. Beside, the geo¬ 
logical soundings made by engineers of the United States through the 
sedimentary accretions of the bars have demonstrated the existence of 
four or five evidently distinct strata, the origin of which runs back to re¬ 
gions of the Gulf, far from one another. Thus one is disposed to recog¬ 
nize in the bar at the Kortheast Pass, or Pass a Loutre, alluvium proceed¬ 
ing from the Alabama River, and the sands of the Rio Grande can be 
identified in the strata obstructing the Southwest Pass. 

From these apparently contradictory arguments we may infer that 
these two causes, the river and the sea, concur to form the mouths of 
the Mississippi, each in its respective limit, and to leave only one 
principal outlet, perhaps sufficient as an issue to its waters, but too 
much restrained and irregular for the necessities of an extensive navi¬ 
gation. These two equally powerful causes do not balance each other 
at any given time. Each has its period of weakness or energy. 

The river in ordinary circumstances, that is to say, at low-water mark, 


70 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


or at mean tide, carries a certain quantity of matter, which is distrib¬ 
uted in the depth of the liquid mass according to its density, the 
finer and more diluted mud being nearer the surface. 

The swiftness of the current near the bottom being much less than 
the swiftness of the upper current, the deposit in the bed of the river 
of all the heavier matter takes place especially when the current ap¬ 
proaches the eighty-feet wall which forms the main body of the bar, 
leaving only an outlet of fifteen or seventeen feet above it. In this 
outlet the water increases, and being compressed and undergoing the same 
pressure, it obeys the laws which cause the contraction of the fluid 
veins. It is not then, therefore, that it deposits the light mud with 
which it is laden, but carries it out to sea a distance of several miles, 
and a wide circle indicates the limit where this mud ceases to color the 
water, and where the sea, after dividing it into minute particles, spreads 
them afar under the action of winds and currents. 

Mr. Charles Ellet recognized at sea the existence of a stratum of 
fresh water, about 7 feet in depth, floating in the waters of the Gulf 
without mixing with them ; and this phenomenon of two distinct cur¬ 
rents manifests itself on the bars, where it is ascertained that under the 
columns of fresh water there is a counter-current of about 8 feet of salt 
water. This new narrowing of the outlet corresponds with a new in¬ 
crease of swiftness, for while the velocity of the river is only 2.6 inches 
at Carrollton, it runs at a rate of three miles at the surface, and nearly 
two miles near the bottom, when passing over the bars. 

The existence of this under-current combines, with the increase of swift¬ 
ness we have alluded to, to render impossible any fresh-water accretions 
during the mean or low-water mark. Then, during this period of mean 
and low water, the river carries to the sea all the alluvium the density 
of which has prevented their deposit in its bed before reaching the 
passes. Nothing remains on the bars. 

It is no longer the same at high water. Then the outlet is no more 
sufficient, the river drives the counter-current before it, and its waters 
occupy the whole passage. But, as its increased swiftness has enabled 
it to transport more numerous and voluminous materials, these, de¬ 
tained in their course by the friction on the bar, and by the resistance 
of the sea, settle on and obstruct the bars. Meanwhile the upper current 
of the river, whose velocity has not been reduced, carries afar in the Gulf 
all the lighter alluvium, which it there leaves to settle in the depths of 
the sea. If while this pressure takes place in the fluid vein a strong 
tide or a storm should drive the sea against the pass, the struggle be¬ 
tween the sea and the river current trying to force an issue, plows up 
and drags away the matter which had deposited itself horizontally 
on the bar; it disturbs it and occasions accidental obstruction at high- 
water mark, and gives birth to those singular phenomena known as mud- 
lumps. 

If the river, during its rising period, partially builds up the bars, 
either by extending them inward or by adding to their height, the sea 
regains its superiority during high tides or great storms; for it piles up 
new materials at the base of what already forms the outer wall of the 
bars. These materials are thus, in great part, restored to their former 
origin; for the greater portion consists of alluvium that the great river 
had furnished, and it is fortunate that such should be the case. The 
argillaceous nature of these materials prevents the accretion formed from 
attaining too much consistence and resisting the causes of destruction 
or removal to which they are exposed. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 71 


Fortunate would be New York if the vast sand bank which is grad¬ 
ually invading its port was of a nature so little resisting. 

This double and irresistible action of the river and the sea, which we 
would describe more minutely if it would not lead us too far from our 
subject, follows and obeys an immutable law of nature, to attempt to 
change which, by any contrivance of man, would bo folly; for the more 
closely we study its working, the more convinced shall we become that 
its field of operation is too vast, and must increase rather than remain 
stationary. 

The gradual growth of the obstructions at the mouth of the river, pre¬ 
viously referred to, has been and still is accelerated, if not entirely caused, 
by the system of levees as now practiced on a yearly increasing scale. 
This system has prevailed over the system of lateral outlets, and, with¬ 
out wishing to discuss at present the wisdom of that preference, we 
make note of it, and only remark, that the mass of alluvium which for¬ 
merly deposited itself in accretions on the swamps of the delta now go 
entirely to the sea. This is doubling the volume of fluvial matter which 
drifts into the sea; it is, therefore, doubling the materials with which 
that indefatigable builder will erect the walls of our bars. 

On the other hand, as the delta projects itself farther out, the various 
mouths of the river are left every day more exposed to the action of the 
winds and currents without protection. It is admitted that any great 
river that does not empty into a bay capable of protecting its mouths 
against the action of the winds and waves must soon be obstructed by 
the formation of bars heaped up by the sea. Such has been the case 
with the Ganges, the Nile, the Mississippi. It is even necessary that 
the surface of the bay should be, to a certain extent, proportionate to the 
volume of water which is discharged in it; if too small, the river does 
not lose a sufficient portion of its swiftness, and comes out of the bay 
still exposed to the contrary influence -of the waves. The bay in that 
case is but an enlarged outlet of the river. 

If the bay is too wide, the swiftness of the stream is quickly reduced, 
and its sedimentary deposit fills up gradually the basin in which it dis¬ 
charges itself. Such is the case with the river Clyde. Some hydrog- 
raphers are of opinion that the vast bay formed by Lakes Borgne and 
Pontchartraiu, and yet called the u Mississippi Sound,” was destined by 
nature to be the real outlet of the river, and that, by closing the outlets 
of its waters in the two reservoirs above and below the city, the natu¬ 
ral course of this navigable highway has been completely changed. 

Whatever may be the case, the progressive tendency of the delta 
toward the sea will only increase the incumbering and obstructive influ¬ 
ence of the winds and currents. The South and Southeast Passes, 
henceforth impracticable for ships of ordinary draught, prove that, 
where this influence is direct and in the course of prevailing winds, its 
effects are alike prompt and dangerous. The North and Southwest 
Passes have thus far escaped this action, only because they have been 
partially protected by their peculiar direction. 

Consequently, notiling can be hoped from the natural agents, either in 
the present or future condition of the mouths of the Mississippi. Far 
from it. We have demonstrated that this condition can only grow worse 
in the course of time. 

Let us now discuss the efforts that have been made to undertake a 
gigantic struggle against forces that are natural, eternal, and necessary 
We will embrace in the same examination the study of the means indi. 


72 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


cated, but not tried. We will find tlie result of this examination in the 
conclusions of the State engineer, Mr. Hebert: 

Let us submit ourselves uot to struggle with the Mississippi. We have no hold over 
it. Our presumptuous efforts can only result in bringing the punishment on our own 
beads. 

The slightest reflection on what precedes will enable any one to under¬ 
stand that the idea never entered the mind of any practical man to 
remove and annihilate those immense masses called bars. Let one im¬ 
agine enormous blocks of mud, having a length of several miles, a width 
varying from one fifth of a mile to one mile, and a height of more than 
eighty feet. Let them be represented propped on the river-side by an 
abutment which is formed by its bed, upon which the deposits of ages 
in the untroubled waters have caused such elevation of that bed that 
its height is eighty feet more than any other point as far up as Baton 
Rouge, although the mean declivity of its surface is 3J inches per mile 
between these two extreme points. In presence of such gigantic obsta¬ 
cles it will be easily understood that all the hope of science and commerce 
has been limited to the excavating of their Upper surface in order to 
procure an open and permanent way to navigation. Consequently a 
regular passage of from 3 to 5 feet more depth than actually exists on 
the ba> s is the extreme height of the ambition of our engineers and our 
merchants. But, as modest as may be this ambition, it is necessarily 
doomed to disappointment, for a sort of compromise has been entered 
into between the sea and the river, by the slow and alternate poising of 
their opposed forces, by which the necessary outlet for the river has been 
fixed at a height of 15 to 17 feet. We canuot go beyond this. 

The first work for the improvement of the passes goes back as far as 
1839. The Federal Government commissioned Captain Talcott, of the 
Corps of Engineers of the United States, to proceed to the opening of a 
regular channel. That officer used in his attempt the ordinary bucket- 
drag ; but circumstances were so unfavorable that he obtained no result. 
In one stormy night twice as much mud was thrown into the Southwest 
Pass as had been taken away after these expensive labors. 

in 1852 the Federal Government made with the Tow-Boat Association 
a contract for the opening of the passes.' This contract was fulfilled, and 
the work executed in twelve months. The means used by the associa¬ 
tion were the harrow and the rake, and the result was successful beyond 
all expectations; a channel was dug 18 feet in depth,and on a length of 
one and a half miles. This process had already been successfully adopted 
on several alluvion rivers in England. 

As, after this result, no ulterior measure was adopted by which to 
maintain the Southwest Pass in this prosperous condition, and the causes 
of the formation of the bar not having ceased to act, the bar naturally 
very soon became as impracticable as ever to navigation. It was again 
a dreadful storm that destroyed the work already accomplished. 

A new effort was attempted in 1850, but upon an entirely different 
principle, and based upon a theoretical conception. The Corps of Engi¬ 
neers of the United States thought that, if it were possible to give the 
river a greater velocity in the locality of the bars, the deposit would be 
swept off far away, and the passage would remain free, without any 
necessity for periodical and expensive labors. This solution cor¬ 
responded with the hypothesis of the formation of the bars by the im¬ 
mediate precipitation of the fluviatile alluvion, without taking into ac¬ 
count the action of the sea. In consequence, Messrs. Craig and Right 
were authorized, by a contract with the Government of the United 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 73 


States, to open a canal, 300 feet wide by 200 feet in depth, in a 
straight line across Southwest Pass, and a similar caual across Pass a 
Lontre. The work in both passes was to be completed in ten months. 
The contractors were, beside, bound to open these channels during four 
years and a half, to begin from the completion of the work. Subsef 
quently the contract was amended by reducing the required depth o 
the channels to 18 feet instead of 20, and by granting an extension of 
time. 

The plan prescribed to the contractors was the closing up of all the 
passes except the Southwest Pass and Pass a Loutre, and the con¬ 
traction of the current by means of oblique dikes, made of strong piles 
placed at a distance of 5 feet, and connected by boards 5 inches thick, 
with crowning boards connecting the heads of the piles to one another. 

The work performed in Pass h Loutre began on the north side 
and extended itself in a diagonal line in the current to a short distance 
from the bar, and on a length of 550 feet. In the Southwest Pass this 
breakwater was not over 3,000 feet in length. These enormous ex¬ 
penditures gave no result, and the contractors had to give up the work. 
JBut even had a result been obtained, it could only have been temporary, 
like everything else that has been attempted to modify the condition of 
the passes. 

The problem of the outlets of the Mississippi had been assimilated to 
that of the mouth of the river Clyde, where a breakwater made of stakes 
supporting a stone-work had given excellent results. The assimilation 
was incorrect, inasmuch as the Clyde is protected at its mouth against 
the action of the waves by the firth into which it empties, and that the 
only cause of its accretion was the too great extension of the firth, as 
compared to the volume of water proceeding from the river, which ar¬ 
rested its swiftness and determined the precipitation of the deposits. 
We will observe, beside, with Mr. Hebert, that any wood-work placed 
in the waters near the Gulf would be destroyed by the worms in a few 
years. 

After this fruitless attempt the contractors created, during some time, 
a navigable channel by employing the expensive process of blasting. 
But all this was again made useless by the incessant but silent working 
of the forces which cause the formation of the bars, and Messrs. Craig 
and Bight had to abandon definitely their contract. 

Since that experiment, all the science of the engineers who propose 
to improve the bars is confined to the drag to break up the accretions 
and carry them out to sea, or to the use of the harrow, to disturb them, 
confiding to the current the task of carrying them out. In both of these 
systems, so little different from one another, it is well understood 
that this work can only be made permanent by means ot an annual 
fund created for this ever-recurring task. 

Captain Duncan’s consists in the purchase of a dredge-boat, costing 
$50,000, and operating successively on the two bars during four months 
each. The calculation of the cost attendant on this work shows, after 
deducting the cost of the boat, the net sum of $105,270. 

Mr. Hebert opposes this plan for various reasons, which are well 
worthy of attention : 

u First,” lie says, “ this work would demand heavy expenses for boat and machinery; 
and when t he mud will have been detached from the bottom it will have to be put in other 
boats w T hicli will carry it out to sea. Many laborers will be needed, and the process 
will be very slow. Secondly, wdiile these boats will be employed in the channel, they 
will incumber it m such a way that ships will not be able to pass, and commerce will 
suffer.” 


74 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Mr. Hebert’s plan, which is based upon the use of the scrapers and 
the harrow, has not, he thinks, those inconveniences. We cannot agree 
with him on that point; for the two boats which he proposes for the two 
passes and the management thereof, we find, again, an expense ot $150,000 
will have to be renewed annually. The difference for such an object is not 
much. As to the presence of a boat in the channel, it seems to us equally 
troublesome in either system. 

But what induces us to embrace both in the same condemnation is 
the judgment passed upon them by the facts we find in the past. Was 
it not the drag that Captain Talcott used in 1838 and 1839 ? A night 
was sufficient for the destruction of all he had achieved. Was it not by 
means of the harrow that the Tow-Boat Association opened a temporary 
passage ? A single storm sufficed to till it anew. 

Can nothing better than such uncertain and feeble results be obtained 
in this enlightened age, for the security and benefit of the immense 
commerce entering into and issuing from the Mississippi—a commerce 
already counted by hundreds of millions of dollars, and destined, with 
proper facilities for the safe and speedy entrance and departure of ves¬ 
sels, to vie with that of the largest ports of the New World in richness 
and extent? We believe there can; and we shall proceed to examine 
whether an outlet from the Mississippi cannot- be obtained by means 
and through a way more sure and durable than any that have yet been 
proposed. 

All the investigations hitherto made convince us that we are powerless to 
improve permanently the outlets of the river , either by acting directly on the 
passes or by modifying the general course of action of the river itself; and 
ive are again and again compelled to admit that the Mississippi has not , and 
cannot have , a reliable , adequate outlet at the extremity of its course. 

Before we attempt to create another, let us examine the consequences 
of this proposition on the commerce of New Orleans. 

NECESSITIES OF A COMMERCIAL OUTLET TO THE MISSISSIPPI. 

The free navigation of the river by ships equal in size to those which 
frequent and supply all great ports, that is, of an average tonnage of 
1,000 to 2,000 tons, has always been the hope and the dream of the com¬ 
merce of New Orleans. The numerous failures experienced have not 
yet destroyed that hope, nor have the sad lessons of reality been suffi¬ 
cient to dispel the dream. This illusion has, however, cost dearly to our 
port. Our commercial navigation offers the singular anomaly of one of 
the greatest foreign exportation trades on a distance so considerable as 
the width of the Atlantic, carried on by means of small ships, whose 
average tonnage does not exceed G92 tons. We will have occasion soon 
to refer to the deplorable consequences of this singularity. 

If at the beginning of our great commercial enterprise, which does 
not go back to a ve^remote date, public opinion had been as determined 
as it is now, concerning the impossibility of opening the mouths of the 
Mississippi to the navigation of large vessels, the force of circum¬ 
stances, the encouragement found in the admirable condition of our 
port, and urgent necessity, would have induced the founders of this com¬ 
munity to adopt, at an early date, the only measure that reason points 
out, and which we want to attempt now. They ivould have left aside the 
passes , and ivould have a direct outlet from the river. For the last forty 
years New Orleans would have been the first port of the United States. 
New York would have only occupied the second rank. It is not too late 
to open our eyes to truth, and to act with energy and promptness, no 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 75 


longer to conquer anew a rank that has escaped us forever, but to avoid 
the consequences of our former and fatal errors. It is no longer the 
question of glorious predominance, and of a rank to be assumed. The 
question is to defend our existence, and to preserve for our wharves the 
produce disputed by unrelenting competition. Our rivals act and create; 
as for us, we are content with making official reports on the subject, and 
when these reports uniformly conclude by an appeal to Congress, we 
wait, with our looks turned toward Washington City. 

Previous to the war with England New Orleans had not awakened to 
her great commercial existence; the greater portion of her commerce 
found a channel through Lake Pontcliartrain and Lake Borgne. When, 
for the defense of the country, it became necessary for the Federal Gov¬ 
ernment to close those two outlets of the river above and below the city, 
nothing was left to the latter except the way by the passes. At that 
early time the clever speculators of New England understood the im¬ 
mense benefits which a navigation that could only be performed through 
countless shoals, through a maze of reefs whose positions vary inces¬ 
santly, and where the use of a great auxiliary power was indispensable, 
would promise to a piloting and towing association. Thus it was that 
the burdensome exigencies of pilots and tows were imposed upon our 
newly-born commerce. However, the hope existed, even at that date,that 
the yoke would be thrown off the day when great works will open forcibly 
the mouths of the Mississippi. It was necessary to submit to this for 
the time being, and to conform to it the condition of the commercial 
navigation. Meanwhile navigation in large vessels was abandoned and 
ships of small draught were constructed expressly for New Orleans. 

At last came these attempts at improvements, so long promised and 
so impatiently expected. We have seen that they go as far back as 
1839, and we have narrated the useless labors of Captain Talcott. Dur¬ 
ing that time the deplorable condition of our navigation called from the 
shippers of the interior, from our own and foreign merchants, such nu¬ 
merous and energetic complaints that they suggested the idea of a possi¬ 
ble competition. This consisted in nothing less than to build, at great 
cost, railroads on all the width of the continent to meet the Atlantic 
ports, while the great river, “that moving road,” as Pascal calls it, was 
gratuitously left to us. Moreover, the greater portion of the articles 
which would have been carried upon these railroads consisted of agri¬ 
cultural products of a comparatively small value and cumbersome nature, 
for which the question of rapidity was immaterial. It must be conceded 
that all these motives made the prospect but little encouraging, and 
that it needed all our infatuation to permit a success so doubtful to all 
appearance. 

Notwithstanding the incomparable superiority of the Mississippi over 
all other practical routes, the railroad system began to draw an impor¬ 
tant portion of the produce of the valley of the Mississippi. All the North 
and a portion of the center belong to them ; it is by a net of railroads 
and by the navigation of the great lakes that the grain from the West 
and Northwest, the most colossal mass of agricultural products ever 
thrown into circulation by any country in the world, finds an issue. The 
time may yet arrive when we can again enter the lists and bring back to 
its natural route a certain portion of this immense tonnage. This will 
be when we have a secure outlet for the river with a constant depth of 
water of 22 to 24 feet, together with a direct communication with Eu¬ 
rope in ships of considerable tonnage. To obtain this result, so easy, 
since it only depends on our own will, it is necessary that the commu¬ 
nity should be thoroughly enlightened upon the present condition of the 


76 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


commerce at the mouth of the Mississippi and the consequences to the 
prosperity of our city resulting therefrom. 

We cannot quote, in this respect, a more instructive document than 
that we find in report of the committee of the New Orleans Chamber of 
Commerce, commissioned to visit the bars in February, 1859. This com¬ 
mittee was composed of Messrs. W. Creery, E. L. Wibray, J. B. Morri¬ 
son, G. A. Fosdick, and P. H. Skipwith. 

The amount of merchandise delayed at the bar on that occasion, seek¬ 
ing ingress or egress, was estimated as follows: 


1. For exportation. 


Cotton, bales, 71,985, at $60. $4,319,100 

Tobacco, hogsheads, 3,337, at $150. 500,550 

Sugar, hogsheads, 2,277, at $75..-. 170,775 

Molasses, barrels, 1,575, at $12... 18, 900 

Pork and beef, barrels, 11,309, at $18.•.. 203,562 

Flour, barrels, 11,417, at $5. 62,793 

Lard and ham, tierces, 2,929, at $30. 87, 870 

Wheat, sacks, 3,789, at $1. 3,739 


Total. 5,367, 339 


2. For importation. 

An approximation of value. 2,000,000 


7,367,339 

It will be thus seen (says the committee) that there is now held in check, in conse¬ 
quence of the impediment to navigation above referred to, property worth nearly five 
and a half millions of dollars, the interest of which for a single day, at 6 per cent, per 
annum, amounts to about $1,000. In this estimate no account is taken of the value of 
the ships, nor any but the leading articles of produce; nor the cargoes of the ships 
which have cleared aud are ready for sea, and whose commanders deem it more pru¬ 
dent to remain at the wharves until there is a prospect of getting over the bar without 
difficulty, than to lie at anchor inside or aground on the bar in the crowd of ships, and 
liable to damage. This is a startling array of figures; in itself sufficient, in the opin¬ 
ion of your committee, to arrest public attention and cause the most indifferent to re¬ 
flect on the evils likely to arise from such a derangement of the commerce of the city, 
and which will end in the total ruin of our trade, and even our very existence as the 
emporium of the Southwest, unless prompt and energetic means are adopted for the 
removal of these obstructions. 

Much has been said and written on the subject of the railroads which now tap the 
Mississippi River, and have their termini on the Atlantic shore, and of the injury which 
they are likely to work to the trade of New Orleans, by diverting the produce of the 
great valley of the Mississippi from its natural outlet there ; but these your committee 
have read and listened to without the least feeling of alarm, having an abiding confi¬ 
dence that the Mississippi would continue to be the great highway for the produce of 
the valley which bears its name, aud New Orleans the great depot and point of exporta¬ 
tion, if there was free communication with the Gulf of Mexico for vessels of the class 
required by the yearly increasing necessities of trade; but they must confess that the 
spectacle which presented itself to them at the bar gave rise to grave apprehensions 
whether or not it would bo possible to retain the trade of New Orleans aud maintain 
its position as the greatest exporting city of the Union, unless some measure of relief 
is speedily granted; nor are the movements going on around calculated to allay these 
fears. Already rival cities, taking the advantage of our misfortunes, are putting forth 
their claims to a share of the trade which has heretofore been ours, aud which, we are 
constrained to admit it needs no prophetic eye to discern, must soon seek other channels 
unless these obstructions are removed ; for your committee do not doubt that every fa¬ 
cility will be given by our rivals to those frequenting this port aud mart, which their 
own resources aud all the outside aid they can bring will command. 

In the list of property detained at the bar is comprised one item of nearly 72,000 bales 
of cotton. Some of these outward-bound ships have been detained for several weeks, 
and it is hardly to be supposed that parties in want of cotton will again send their 
orders to New Orleans, if there is the least likelihood of a similar delay in getting it 
to market; and if this community is not alive to its interests, the now famous cotton 
mart of New Orleans will speedily become a thing of the past. Again, the bills of 














IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 77 


exchange drawn against the cargoes so detained will, in all probability, mature before 
the produce arrives, when, by all ordinary calculations, it would have been at band in 
time to meet them, and this is another ramification of the evil which may overtake us 
in the shape of a derangement of our monetary affairs, consequent upon the difficulties 
which parties may experience in raising funds to retire the same. 

Ot the value of these cargoes of the inward-bound ships your committee have no 
data, but they think it may be safely put down at two millions of dollars. Many of 
these ships are laden with goods destined for the West and western trade, and it 
requires but a slight effort of the imagination to picture the loss and inconvenience 
which the owners have suffered by having their goods detained until the proper season 
for their sale is past. These, again, are not likely to order their supplies to be shipped 
via New Orleans until they have the assurance that these impediments to the naviga¬ 
tion have been permanently removed. In looking at the question from this point of 
view, we cau see that the interest of the consumer, although apparently remote, is 
actually near and positive. So large an amount of goods being kept out of market, 
must necessarily enhance the value of those on the spot, and he therefore has to con¬ 
tribute his quota of the loss by the advanced prices which ho has to pay for the.articles 
of import which he requires. 

One month after the visit of the committee of the chamber of com¬ 
merce, the State engineer, Mr. L. Hebert, and his first assistant, Mr. L. 
J. Fremeaux, arrived at the passes to prepare their report to the legis¬ 
lature. 

On the 3d of March, they found three vessels aground on Pass a 
Loutrej one of these, the Mary R. Campbell, drawing 19 feet, had been 
aground sixty days; another, the Avon, drawing 1G£ feet, was on the 
bar since the previous day ; and the third, the Lebanon, drawing 17J 
feet, had been there three weeks. The previous day a large ship, the 
Lancaster, that had been aground forty-eight days, had been at last 
pulled out of that unpleasant fix. Vessels thus remain on the bar 
because of the tortuosities of the channel. Each vessel that runs 
aground causes a diversion and a separation in the current, and conse¬ 
quently the formation of other secondary bars. The strongest tow-boats 
cannot follow the channel in all its irregularities, and thus it is that 
they run aground vessels drawing less water than there is in the channel. 

Arriving at Southwest Pass on the same day, 3d of March, Engineer 
Hebert found at anchor, inside of the bars, thirty-five vessels awaiting 
the possibility of egress. There were also three on the bar and seven¬ 
teen outside, at anchor awaiting to be towed in. There were then alto¬ 
gether fifty-five vessels detained. Here are some interesting documents 
concerning thirty of them: 


* 


Bullion. 

Fanny Forrester 
J. Montgomery. 

Bessel. 

Saint Louis .... 

West Point. 

Bannockburn... 

Potomac. 

Creole. 

Wm. Lord, jr- 

An au. 

E. Merson Smith 

Bamberg. 

Mary. 

J. Morten. 

Huntress. 

Levi Woodbury 


Names of vessels. 


Draught. 

Days of 
detention. 

Feet. 

16| 

8 

18 

24 

m 

9 

18 

24 

16} 

3 

18 

3 

Hi 

10 

17± 

12 

m 

1 

18 

15 


7 

18} < 

7 

18 

22 

18 

22 

18 

25 

18 

15 

19 

26 
























78 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Sheridan. 

Athena . 

Barnabas Webb 

Lockinvar. 

E. F. Gabain ... 
S. E. Pettigrew. 
Ch. Davenport.. 

Victory . 

Arctic.. 

Lady Sale. 

Ocean Monarch. 
Win. Stetson ... 
Czar. 


Names of vessels. 


Draught. 


Days of 
detention. 


Feet. 


181 

22 

17* 

10 

m 

29 

m 

8 

19 * 

39 

19 

26 

m 

1 

18* 

9 

18* 

2 

17* 

1 

19* 

5 

18f 

1 

17* 

. 3 


Between the 28th of February and the 3d of March, at 3 o’clock p. m., a few of the 
above-named ships were taken to sea, but others had been brought from the city, and 
as before stated there were on the 3d of March thirty-five vessels. Two of the ships 
on the bar were much in the way. The Tow-boat Association are busy bringing in 
and passing out vessels, but they have more than they can do, on account of the im¬ 
mense power they are compelled to use, and the long time they have to give to each 
ship. With the large number of vessels now detained, aud those that are constantly 
arriving, there would seem to be no end to the work the tow-boats have before them. 

One more quotation from an official source will be sufficient to prove 
that the commerce of our city suffers from the present state of things. 
The committee of the legislature on commerce and manufactures closes 
as follows its report of the 3d of March, 1859 : 

In conclusion, we beg leave to call your attention seriously to the present condition 
of the bar at the mouth of the Mississippi River, w r hich, at this time, cannot be crossed 
by a majority of vessels coming in and going out, without great labor, cost, and delay. 
We further call your attention to the enormous amount of appropriations from the 
General Government which have been expended in attempts to remove this obstruc¬ 
tion, without any benefit whatever. We therefore recommend, aud hope your honor¬ 
able body will take immediate steps to present this state of affairs to Congress, and „ 
urge action on the part of the proper authorities. 

Independent of the inconveniences enumerated above, some others 
exist that result from the very position of the mouths of the delta, and 
their stretching out in the main sea. 

Their approach is surrounded by difficulties; no shelter protects the 
vessels against the winds aud waves, and the large number of shoals 
that are formed in their vicinity renders the services of a pilot indis¬ 
pensable. 

During at least eight days per month in the winter season fogs pre¬ 
vail of such intensity as to render ingress or egress impossible. Engi¬ 
neer Hebert mentions this obstacle in his report on the 9th of March. 
Speaking oi his arrival at the passes on the 28th of February, he says: 

Here I encountered such heavy and constant fogs that, although I rau from pass to 
pass, taking notes of the shipping, steamers, &c., it wvas only on the 2d and 3d of March 
that I could make the examination of all the bars. 

Moreover the necessity of towing carries with it, as a peremptory con¬ 
sequence, frequent damage, and an extraordinary rapid wear and tear 
of the vessel. The effect on a ship’s hull of the traction of one, and 
sometimes several tow-boats, pulling her, and making her force her way 
through a muddy mass, whose surface is generally soft, but which is 
sometimes hard at a depth of 18 inches, may be easily imagined. We 
have seen on the 3d of July last, at the Pass a Loutre, four tow-boats 





















IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 79 

hitched to a single vessel, and applying to her four different angular 
forces. Each of these tow-boats was of at least 400-horse-power ; the 
ship’s draught was only 17 feet 8 inches. 

Finally, the cost ot this so destructive auxiliary force is exorbitant, and 
while it makes the fortune of thb rival companies that carry it on, it 
burdens our port with a tax exceedingly onerous in our competition 
with Atlantic ports. It can be estimated at 83 cents per ton for vessels 
of small tonnage; a ship of a thousand tons pays for towage up and 
down the river $1,043, and must bear an additional charge of $150 
if compelled to take a second tow-boat to cross the bar. 

Official documents estimate the tax levied by towage and pilotage 
on the commerce of New Orleans at over $2,000,000. And this tax has 
for its only result to prolong an expedient which compromises our pres¬ 
ent and future existence. 

Let us recapitulate the various charges in an act of accusation which 
might be made by the commerce of New Orleans against the navigation 
of the passes. The access to the passes is difficult and dangerous. It 
is unprotected and exposed to every wind. Pilotage is of imperious 
necessity. The condition of the passes makes it necessary to employ 
tow-boats, the use of which is as ruinous to the solidity of the vessel as 
it is expensive. 

The tow-boats themselves are of insufficient number to meet the ne¬ 
cessities of navigation; besides, they cannot bring over the bars with 
anything like regularity ships drawing more than 16 feet. 

The vessels thus detained on the bars are exposed to damage, the risk 
of which augments greatly the rates of insurance. 

During all the time of their detention there is a loss to the ship-own¬ 
ers in interest on the ship’s capital; in the decrease of an annual circu¬ 
lation of this capital, and in the increase of the crew’s wages and con¬ 
sumption of stores. The tardy arrival of his merchandise in the 
market destroys all the favorable chances of speculation of the shippers 
of the cargo, the merchandise is exposed to deterioration by the decay, 
and he runs also the risk of seeing his drafts on foreign markets returned 
to him protested. 

All these, causes of complaint fall back upon the merchants of New 
Orleans, by depreciating our market, and causing our customers to send 
their orders to other markets, where they are sure to be filled with cer¬ 
tainty and promptness. 

The committee of the chamber of commerce was, therefore, right 
when it stated that New Orleans could only preserve her position as the 
great mart of the Southwest on condition that a free communication 
with the Gulf of Mexico be established; note this free communication 
does not and cannot exist through the passes. 

The committee adds that this facility of communication must exist for 
ships of the class claimed by the ever-increasing wants of commerce. 
This judicious remark leads us back to that which we made on the sin¬ 
gular character of the commercial navigation of New Orleans, giving 
rise to one of the greatest shipping enterprises in the world, that of 
American cotton to Europe, across the Atlantic, in ships of compara¬ 
tively small tonnage and slow speed. 

We have explained how the state of the passes had imposed these 
hard conditions upon us. We will state the facts by means of the offi¬ 
cial figures furnished to us by the statistics of the business of the port. 


80 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


1.—Exportations. 


Year. 


1858—’59 


1859-’60 



Vessels. 

Exported tonnage. 

Tonnage. 

'American vessels to foreign ports ... 

Foreign vessels to foreign ports. 

Coast trade. 

834 

336 

1,015 

Exported tonnage. 

.do. 

.do. 

641, 392 
167, 964 
409, 872 

Total. 


2,185 

1, 219, 228 

| American vessels to foreign ports. -.. 

Foreign vessels to foreign ports. 

Coast trade. 

Exported tonnage. 

.do. 

.do. 

958 

334 

943 

713, 588 
180, 733 
354, 205 

| Total. 


2, 235 

1, 248, 526 




Value. 


} $101, 634, 952 


2.—Importations. 


Vessels. 

Imported tonnage. 

Tonnage. 

694 
345 
1, 023 

Imported tonnage. 
.do. 

492, 522 
167, 588 
521,972 

.do. 


2, 062 

1,182, 082 

Imported tonnage. 
.do. 

696 

328 

1 028 

458, 310 
178, 286 
575, 433 

.do. 


2, 052 

1, 212, 029 



Year. 


1858-’59 


1859-’60 


American vessels from foreign ports. 
Foreign vessels from foreign ports... 
Coast trade. 


Total. 


r American vessels from foreign ports. 

Foreign vessels from foreign ports... 
< Coast trade. 


I 


Total. 


Value. 


' $16,678,092 


20, 634, 393 


Total Dumber of vessels circulating across the passes has therefore 
been 4,247 in 1858-’59, and 4,287 in 1859-’60, both for exportation and 
importation, and the tonnage has been 2,401,310 tons in 1858-’59, and 
2,460,555 in 1859-’60. 

The comparison of these two years gives us an average of 565 tons 
per vessel for the preceding, and 574 tons per vessel for the current, 
year. 

But if we examine especially the exportations to foreign ports, we 
find in 1859 1,170 vessels exporting 809,356 tons, which gives us an 
average of 692 tons per vessel. In 1850 there were 1,292 vessels ex¬ 
porting 894,321 tons, making again an average tonnage to foreign ports 
of 692 tons. 

It will be seen that this tonnage, so small when compared to that of 
Atlantic ports having vessels of 1,200, 1,500, and 1,800 tons, is required 
by the nature of the outlets of the Mississippi. In fact, it can be ad¬ 
mitted as an average that a vessel of 600 tons draws 14^ feet of water; 
one of 800 tons draws 16 feet of water; one of 1,000 tons draws 18J 
feet of water; one of 1,200 tons draws 20 feet of water; one of 1,500 
tons draws 21 feet of water. Gan such a state of things continue at a 
time when it is demonstrated that the greatest profits are earned by 
the largest ships ? 

It is evident that, due allowance made for proportion, large vessels 
cost less to build than small ones; they take less materials, secure a 
greater economy in the general expenses, and are safer. All possible 
advantages will then be found in substituting large vessels for small 
ones wherever the natural conditions of navigation will permit this 
change. As for ourselves, until we shall have created an outlet to the 
Mississippi, with a regular depth of 22 to 24 feet, we will find it impos¬ 
sible to realize this progress. 

Ships of a large tonnage may, it is true, run the same disadvantageous 


















































































IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 81 


cliances as smaller ones, such as returning in ballast; but an examina¬ 
tion of the preceding statistics shows that the difference between the 
tonnage of exportation and importation is small, and that the difference 
will diminish as soon as the direct trade of large ships between our port 
and Europe will compel those ships to bring to us directly, in order to 
make their return cargoes, those articles of importation which we are 
now receiving indirectly and by the way of the North. 

It the value of our importations be compared to that of our exporta¬ 
tions, the following results will be found : 

In 1858-’59, importations, $10,678,092; exportations, $101,634,952; 
difference, $84,956,860. In 1859-00, importations, $20,634,393; exporta¬ 
tions, $108,393,567; difference, $87,759,174. Now, in 1858-’59 we re¬ 
ceived, in specie, $15,627,017; and in 1859-60 we received, in specie, 
$8,444,857. There is, therefore, a balance in our favor in 1858-’59 of 
$00,329,844, and in 1859-’60 of $79,314,317. 

This balance is refunded to us from abroad in the shape of merchan¬ 
dise exported to the North, which makes good use of it in the settling 
of our accounts with the interior, thereby making double profits—first, 
as brokers between Europe and ourselves; and, secondly, between us 
and our customers of the interior, without counting their profits as ship¬ 
owners and freight-carriers. 

From the day that a free access to our port will permit a large direct 
trade with Europe, this balance will in great part come to us directly, 
and it is from our wharves that the distribution of these goods will be 
made; the mean value of the ton of imported goods being $14.11 for 
the year 1858-’59, and $17.02 for 1859-60, while the value of exported 
goods per tou is $83.36 for 1858-’59, and $86.82 for 1859-’60. There 
will be a business of importation equal to about that of exportation, but 
of fourfold tonnage. 

Then it is that, to furnish return freights to this increased number of 
arrivals, we will have to struggle, in our turn, to get back a portion of 
those agricultural products of the West which the Northeast has at¬ 
tracted to its ports by its railways; but then we will have conquered 
new advantages, and, being able to offer to those products an easy and 
regular outlet, at direct transportation to Europe, and ships of a large 
tonnage, we will find ourselves engaged in competition altogether ad¬ 
vantageous to us. The railroad interest of the North already feels this. 
To sustain their roads it has been found necessary to increase the tariff, 
and under this increase of freight we find the following results in the 
comparative transportation of a cargo of 3,000 barrels of Hour shipped 
from Cincinnati to Liverpool by the way of New York and by the way 
of New Orleans: 

From Cincinnati to New York, $4.75 per barrel.) $ f > 25 

From New York to Liverpool, 50 cents per barrel. f ® 

From Cincinnati to New Orleans, 50 cents per barrel. ) $1 46 

From New Orleans to Liverpool, 96 cents per barrel.1 

Difference in favor of New Orleans, 79 cents per barrel. 

This difference will be still greater when our trade will be direct and 
carried on in large ships, and independent of the passage over the bars 
and the attending charges. 


CANAL BETWEEN THE MISSISSIPPI AND THE GULF OF MEXICO. 

Section 1 .—General conditions. 

The Mississippi has no outlet adequate for its commerce, and it is im¬ 
portant that one should be created without delay. These are the two 

H. Ex. 220-6 







82 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


propositions we have demonstrated. We have now to describe this ar¬ 
tificial outlet, and to study it with the attention which its importance 
deserves. 

Let us specify, first, the conditions that it must satisfy. 

1st. It must free navigation of all the difficulties which surround the 
mouths of the river; it must, therefore, be a certain distance above the 

passes. . 

2d. It must not lengthen the term of navigation in the Gulf of Mex¬ 
ico, a sea so dangerous and exposed to gales. It must, therefore, admit 
the vessels in the river as near as possible to its mouths. 

3d. It must not, moreover, be too far from the natural mouths of the 
river, in order not to create too great a difference of level between its 
point of junction with the river and its junction with the sea. 

4th. It must be placed at a point on the river where there exists no 
battures and no fears of battures forming subsequently. 

5th. It must be on the shortest line between the river and the sea, on 
condition, however, that this advantage shall not be compensated by a 
considerable increase in the expense. 

Oth. It must present, at its opening on the sea, natural shelters to 
protect the approach of vessels. 

7th. It must, besides, offer a direction little inclined with that of the 
wind prevailing during the greater part of the year. 

8th. It must open on the sea at a point where no accretion and .no 
decrease in the present depth of water are to be feared. 

9th. It must offer to vessels secure anchorage, so they may be in 
safety outside the canal. 

10th. It must free vessels from all necessity of pilotage, and, con¬ 
sequently, avoid their circulation among the islands, keys, and reefs, 
which in the passes require the services of a pilot. 

11th. It must also do away with the necessity of towing, at least as 
far as the river, where the wind often permits vessels to ascend directly 
from the English Town as far as New Orleans. 

12th. It must have a constant depth of 22 to 24 feet of water, in order 
to permit the access to the river of ships of the greatest tonnage. 

13th. It must be forever secure, by its conditions of existence, from 
those perturbations which render the passes impracticable to the navi¬ 
gation of large vessels; that is to say, from the action of the sea, from 
accretions from the river, from sand-banks formed by any agency. 

It will be seen from the description we are about giving of the pro¬ 
posed canal, and from its topographical conditions, that it will satisfy, 
strictly and precisely, all these exigencies. 

Section 2 .—Topographical and hydrographical description . 

When, going down the Mississippi, we arrive at Fort Saint Philip, 
we see the majestic course of the river developing itself on a length of 
eighteen miles, as far as the head of the passes, without sinuosities or 
turns. The mass of water moves always in the same direction, without 
any sensible inflections in its banks. But as the current came from the 
southwest, and has inflected to the southeast from the bend of the forts, 
the result is that its greatest swiftness and depth are near the left bank, 
while the water is smoother and deposits its accretions near the right 
bank. From three to eight miles below the fort repeated soundings 
have given us depths of 24, 25, 26, and 28 feet, at a distance of 20 and 
25 feet from the bank ; 20 feet farther the lead sinks to 62, 71, and 87 
feet. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER 83 


It we stop seven miles below Fort Saint Philip, that is to say, pre¬ 
cisely on the 90° 3P longitude west, we are at a mean distance of twenty- 
two miles from the passes, which, from the declivity assigned to the 
river, to wit, 3J inches per mile, would represent a difference of 7J feet 
in the level from that point to the surface of the Gulf. Levelings made 
by us between this point and the Gulf show that it is only 3 feet higher 
than the Gulf at mean tide. It is therefore possible to shorten the nav¬ 
igation of the river twenty-seven miles at this point, having to make 
up a difference of only 3£ feet declivity at mean water, and 7 feet at the 
h i gl i est w ater-m ark. 

This point being chosen at the head of the canal fulfills completely the 
first three conditions mentioned above. Let us see if it can satisfy, 
equally, the others. 

If from the top of one of the few huts to be found on that bank, upon 
which, from Fort Saint Philip to the sea, there exists no important es¬ 
tablishment except the salt-works opposite the Jump—if from this ob¬ 
servatory we turn our back upon the river and we look around us, we 
will see, extending indefinitely to the horizon, a scene of extreme monot¬ 
ony. The left bank of the river from the fort to the head of the passes 
is a mere neck of land hemmed in between the waters of the Mississippi 
and those of the sea. Its width, except at few points, does not exceed 
a mile, and at other points it is narrowed down to a few arpents. An 
additional mile may be considered as a dependency of the main land, al¬ 
though cut up in every direction by canals, lagoons, and bayous of an 
average depth of two or three feet during tide time, and which are trans¬ 
formed into mud or sand banks during low tides. Beyond this is a 
series of small bays from three to eight feet deep, and studded with a 
quantity of islets, between which there opens deeper passes or deposits— 
accretions upon which numerous oyster-banks are formed. 

On the right, on the east line, one of these islets, Bird’s Island, of 
more importance than the others from its length, runs from north to 
south a distance of four miles; on its eastern point a watch-tower has 
been built, which commands a view of the sea. Going up from east to 
north, a long sandy beach, known as Sand Island, forms the limit of these 
low lands. 

In the direction of the northeast, the last of these islands, called the 
Pavilion Island, fronts an island situated six miles off at sea, and to 
which we will have occasion to refer; it is Breton Island. 

.To the left of this islet another neck of land, called the Hard Batture, 
runs out to meet an island, two and one-half miles long, Grandes Co- 
quilles Island, which is in the due north point, and is only separated by 
a channel from the smaller Coquille Islands connected in low water 
with the mainland of Fort Saint Philip. 

It is, therefore, in this semicircle, the center of which we have placed 
on the river seven miles below Fort Saint Philip, and the circumference 
of which runs from the southeast to the northwest, that a real archipel¬ 
ago of islands and of lands cut up by lagoons and bays, but uniform in 
their aspect and their nature, is comprised, evidently created by sea-de¬ 
posits, but with materials furnished by the Mississippi; they reveal to 
a geological study the character of the marly accretions to be found in 
all deposits of the river. The bottom of the bays and lagoons, covered 
at certain points by a soft mire which has not yet hardened, is every¬ 
where else perfectly hard, and the purest clay sticks to the lead. All 
these lands, scarcely out of the sea, and which it covers in its usual 
tides and destroys or tears up in its angry moods, only offer to the 


84 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


eye tlie monotonous vegetation of sea-weeds, graminivorous plants, and 
mangroves. 

The radius of this semicircle, from its center on the river to Pavilion 
Island, is of six miles. It is on this radius that the projected canal 
runs. It cuts first the two miles of solid land, crosses the large bay in 
that part of it where the water is lowest, crosses a prairie one mile 
wide, and, pursuing its course through the lagoons and mud-banks, 
it reaches Pavilion Island, having its outlet in the pass of Breton 
Island. 

It may appear singular that we should have chosen this point of the 
coast when we have already stated that three miles below the salt¬ 
works the neck of land has only a width of a few arpents between the 
river and the sea; but a simple reflection will justify this apparent con¬ 
tradiction. The object in view is not simply to cut the canal to the sea, 
which may be done by cutting through a length of 1,000 feet, but it is 
to open it on the deep sea, that is, at a point where large ships drawing 
22 to 21 feet can have easy access. Outside of the main-land there is 
a border of batture, which in some places projects twelve or fifteen 
miles, and beyond this batture, whose conventional line is at a depth of 
12 feet, the declivity is sometimes so small that a long distance must 
be made before the necessary depth of water can be met. 

The distance of six miles which we have found for the line of the 
canal is the shortest between the river and the deep sea that can be 
formed from the forts to the passes, and it is even necessary, in front of 
Pavilion Island, to dig and continue the canal through a batture for a 
distance of 3,000 feet to arrive at the required depth. 

Another circumstance, altogether exceptional, militates in favor of 
this side. Hydraulic works or works of embankments made in 2 or 3 
feet of water may be considered as made on land ; while those made 
in 8 or 12 feet of water are extremely difficult and expensive. Now, on 
the line indicated, about three-fourths of the passage are made on the 
land, and for the other fourth, the average depth of the sea does not 
exceed 2 feet. This plan combines, then, the advantages of the mini¬ 
mum of distance and the minimum of cost. 

Let us examine the access to the canal from the seaside: 

We have already said that by following the northeast liue, which is 
that of the canal, there would be found on the main sea, and at a dis¬ 
tance of about six miles from Pavilion Island, an island known as 
Breton Island. This island, which had formerly a length of six miles, 
and was then occupied by a colonist living with his family in the midst 
of the vast Gulf, was cut off by a sea-storm that took off from it an islet 
of half a mile in length, on which a watch-tower has been raised, which 
would be replaced by a light-house. As cut up as it is, this island, with 
the batture that extends on its right and left, has a length of ten 
miles, running almost straightly from east to west, and forming conse¬ 
quently an excellent shelter for vessels against north and northeast 
winds. 

The coast of the river above the fort, and the large peninsula of Lake 
Borgne, afford protection against the northwest wiuds. 

The coast of the river below the fort shields the canal from southeast 
winds. 

Finally, the south winds are intercepted by the large eastern opening 
of the delta. 

The head of the canal is therefore exposed to the east wind alone, and 
it is precisely this wind which will bring the vessels from the main sea; 


IMPROVEMENT OE MOUTH OF THE MISSISSIPPI RIVER. 85 

it can only facilitate their arrival and bring them in a direct line to the 
port. 

The direction of the canal being northeast, it will be seen that the • 
ships with an east wind will sail directly for the canal with the wind 
over the quarter, a very favorable direction, indeed, both for facility of 
maneuver and speed. The pier that terminates the canal opens in a 
semicircle, to afford ample and convenient room. 

The existence of natural shelters being thus established, can we de¬ 
pend equally on the depth of water in the channel formed between 
Pavilion and Breton Islands? It is principally that point which we 
have investigated. 

Besides numerous soundings in all that region, represented graphic¬ 
ally, we have inserted in the plans the series of soundings from the head 
of the canal to the watch-tower on Breton Island. This line consists of 
the following points: 20 feet, 36, 35, 36, 30, 34, 19, 14, and 12. These 
last three soundings are in the vicinity of the batture of Breton Island, 
the former occupying a breadth of four miles. We have also (although 
it was one mile north of the canal, and consequently of no great impor¬ 
tance) determined a second line from the most advanced point of thereof 
of Breton Island and of the island of the Hard Batture, where that pass 
is narrowest, and we have formed the following figures: 21, 36, 32, 28, 
32, 32, 36, 10. It will be seen that ships will have certain access to the 
canal with fully sufficient water. 

But with the continual changes made by the Gulf in that region, is 
there no fear of the future creation of obstacles, such as those that ob¬ 
struct the passage of the river ? We will reply to this query first by ar¬ 
guments, then by facts. It is very true that the tendency of the sea is 
evidently to fill up all its eastern portion along the river, and to fill up 
gradually all the lagoons so as to form them into main-land. If it de¬ 
stroys accidentally, it creates constantly, and for this very reason cer¬ 
tain passes must necessarily remain where the swiftness, and conse¬ 
quently the depth, will increase instead of diminishing. Such is the case 
with tile two passes that exist west and east of Breton Island, that is, 
on one side between that island and the promontory caused by the 
canal, and on the other betweeu that same island and the great batture 
which begins at Grand Gosier Island and serves without interruption 
as a basis to the archipelago of the Ghandeleur Islands. It is by these 
two passes alone that communication can be obtained between the 
Gulf and the Mississippi Sound within one degree of longitude. 

So much for arguments. As to the facts, the comparison of the 
soundings made in 1827 and consigned on the fine map of the Gulf of 
Mexico, by Mr. Edmund Blunt, w T ith the soundings made by us, prove 
that the depth of water has increased in the west pass of Breton Island 
since that time. These first soundings give 36 feet only on one point of 
the coast; everywhere else they give 18 and 24 feet. 

Among all the advantages we have pointed out in this predestined lo¬ 
cality, there is one that we have mentioned too concisely, and which plays 
too important a part that we should not dwell upon it now. It is the 
nature of the sea-bottom and of the soil of the island which the canal 
will have to cross. Beiterated geological soundings that have uniformly 
given us 14 feet of sand-clay enabled us to verify that it is impossible 
to find a species of clay more firm, more homogeneous, and more resist¬ 
ing. The anchor bites freely, and once imbedded in it, runs no risk of 
dragging. The vessels are, therefore, certain of being able to lie at an¬ 
chor outside of the canal as long as may be desired, under shelter of 
either Breton Island or Bird Island. 


86 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

The precious quality of this soil will be again evident when we take 
up the question of construction. 

These grand conditions once determined, their consequences may be 
* drawn naturally. The vessels arrive from the high sea into a sort of 
gulf, opening due east, and circumscribed to the south by the northern 
bank of Pass a Loutre, to the west by the river and Bird Island, and 
to the north by Breton and Grand Gosier Islands. In this gulf can¬ 
not he found a rock , a reef\ or an islet. Its depths vary in the mean line 
90 to 36 feet. The light-house on Breton Island and that on the pier of 
the canal will point out the entrance to the latter. There will he , there¬ 
fore, no necessity for pilots: no port will ever have an easier and more 
direct access. 

It is useless to add that, until their entrance in the canal, the ships 
will have no need of tows. Once in the canal, the towing will be per¬ 
formed by means of locomotives running on a railway built on the top 
of one of the levees. It is, therefore, only after their arrival in the 
river that the ships will, if the wind is not favorable, employ tow-boats 
to ascend the river. 

Of ail the conditions we have set forth as necessary to an artificial 
opening of the Mississippi, two yet remain to be fulfilled—the creating 
of a depth of 22 to 24 feet, and the assurance that this depth cannot 
be altered or reduced by either the sea or the river. 

These two conditions do not depend on topographical or hydrograph¬ 
ical data, but on the construction of the canal itself. 

Section 3.— Draught and construction. 

It may be asserted with confidence that no work more important in 
its consequences has ever presented fewer difficulties of execution, and 
involved less cost, than the canal of which we have demonstrated the 
necessity. Consequently, its description need not be long or compli¬ 
cated. 

First, the difference in declivity between its two extremes is of 4.J feet; 
the difference of level between the waters of the river and those of the 
sea is only of 3 feet, in ordinary conditions. When the river rises, the 
sea may be below the level of the river as much as six feet. 

The slope of 4| feet on the horizontal line is almost entirely level 
from a distance of 3,000 feet from the river; it is therefore reclaimed by 
a single lock, and outside of this the canal may be considered as being 
perfectly level. But for the necessity of protecting the talus against 
the surf of the sea, there would be no necessity for another sluice at the 
other end. 

It is an entirely level country, with no obstacles to overcome, no 
trenches to be made, no rivers to be crossed, no excavations to be made. 
Its alimentation presents no difficulties; no fears need be entertained 
of filtrations or leaks occurring, save those that might affect the solidity 
of the work. It is in truth a gigantic ditch, unsheltered, perfectly rect¬ 
ilinear, and of complete uniformity on a length of six miles. It will be 
a great undertaking only by its dimensions and its results. 

To determine these dimensions we must remember the object of the 
canal, which is to open a large road to sea navigation, to ships and 
steamers of the greatest size; to continue in some way the draught of 
the deep sea and of the river without sensible interruption. 

But few examples of analogous works can be consulted by way of 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 87 

comparison, and among them only one has been executed, another is 
now in course of execution; the two others are as yet but projects. 


Canals. 

Length. 

Width at 

water-line. 

Width of 

bottom. 

Depth. 

Number 

of sluices. 

Width of 

sluices. 

Length of 

the locks. 

• 

Caledonia Canal. 

Canal of tlie Isthmus of Suez. 

Canal of Nicaragua, (Garella’s project). 

Miles. 

ill 

90 

Feet. 

110 

300 to 195 
134 
147 
100 

Feet. 

50 

208 to 103 

Feet. 

20 

23 

21 

23 

24 

Feet. 

24 

2 

Feet. 

40 

63 

Feet. 

172 

300 

Canal of Nicaragua, (Napoleon’s project) .. 

Canal from Mississippi River to the Gulf. 

82 

6 

30 

32 

3 

47 

80 

210 

400 


We owe some explanations on the remarkable differences presented 
by the dimensions proposed by us compared with the others in the 
above table. 

The prevailing thought in our mind has been to leave free scope to 
the creations of the future, and, while remaining within the limits of 
what is possible and reasonable, to give a wide margin to the already 
manifest tendency tojconstructiug very large ships. Therefore, for all 
the dimensions claimed for their admission, we have gone beyond the 
given corresponding figures for the other canals: 24 feet draught at 
low water; 400 feet locks 5 80 feet of openings to the sluices. We have 
taken as a basis for these speculations on the future, the dimensions 
of the largest steamer ever constructed, except the Great Eastern. 
The Adriatic has a length of 345 feet and a width of 75 feet outside the 
wheels. She draws 23 feet of water and measures 4,144 tons. 

The Great Republic, the largest sailing-vessel existing, draws 23 feet 
and has a length of 302 feet and a breadth of 48 feet. 

Some time will elapse before New Orleans can see vessels requiring 
such outlets arrive at her wharves; but, at all events, if such should 
come she will be able to admit them. However, there is a figure for 
which we have remained far below the large sea-canals; it is that of the 
width of the canal. It is only 100 feet; that is 10 feet less than the 
narrowest of these canals, the Caledonian Canal. . 

It must be known, first, that the Caledonian Canal, however small its 
section, gives access to the largest merchant-ships and to steamships 
and propellers of a large tonnage. Moreover, in its length, which is of 
fifty nine miles, comprising thirty-eight miles in Lakes Loehy, Oich,aud 
Ness, there is much circulation in opposite directions. It is, then, nec¬ 
essary that two large ships should be able to pass each other. The 
same condition exists in all other canals mentioned. 

Such is not the case with our Mississippi Canal. Circulation there 
can only take place in one direction, according to whether the towing 
locomotives are going from the river to the sea or from the sea to the 
river. By this combination there is a gain of one sluice, and for a long 
time to come circulation will not be rapid enough to require othei means. 
Thus a convoy of ships arrives from sea and enters the neck formed by 
the two piers. The locomotive takes hold of it and tows it to the 
nearest or seaward sluice, which opeus, and the convoy enters the locks. 
The gates of the seaward sluice close; those of the head sluice open ; 
the level is formed and the convoy enters the river. Then the vessels, 
awaiting at the wharf on the river, avail themselves of this leveling to 
enter in their turn into the canal, and they are towed to sea. 

The result from this system of working is that the width of 100 feet in 
our canal is equivalent to a width of 200 feet in canals where ships 





























88 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

meet and cross each other. Let us add here, moreover, that toward 
the center of the canal will be found a basin, 600 feet long and 200 feet 
wide, to be used as a wet-dock 

It will be easily understood that this system would have been impos¬ 
sible had the canal had a greater length. The time necessary for the 
towage would have occasioned too much delay to ships awaiting ingress 
or egress. 

According to the table already quoted the movements of import and 
export nearly balance; there was in 1858- r 59 2,062 arrivals and 2,185 
departures, and in 1859-60, 2,052 arrivals and 2,235 departures. 

In the month of November, when this movement was most animated, 
267 vessels arrived, to wit, 152 ships, 40 barks, 18 brigs, 29 schooners, 
and 28 steamships. This gives an average of 9 per day and as many 
departures. By doubling these figures the result would only be 18 ships 
in each direction, or a daily circulation of 36 ships, which, by taking 
the average Of 574 tons per ship, would give 20,664 tons. 

The time necessary to cross the two sluices being about fifty minutes, 
it will take the locomotive one hour and ten minutes to take the vessels 
and run the six miles. This moderate speed has for object not to injure 
the embankment; each trip will then occupy two hours. 

At the rate of twelve trips per day it is three ships, or little over 1,700 
tons per trip. Nothing can be more practicable than these calculations, 
although they correspond to a circulation double of that which takes 
place at the time of the year when the commercial movement attains its 
maximum. 

If we follow the plan of the canal in its short and simple line from the 
river to the sea, we will find at its head, on the Mississippi, a light-house 
placed on the upper embankment; the object of this light house is to 
point out to ships coming down where they must stop. There is to be 
formed from this embankment, running to a length of half a mile, a 
wharf along which the ships, and tows they may need, will line them¬ 
selves. Behind the wharf, and at the head sluice, is placed the house of 
the keeper of the canal and the custom-house office; opposite, on the 
other side of the lock, is the building used as the locomotive-depot, and 
containing a machine-shop and a store house for the urgent repairs and 
supplying of the vessels. 

The head sluice, of a width of 80 feet, gives entrance into a lock 400 
feet in length, closed by the middle sluice; the latter gives passage 
into a channel formed by levees in embankments. From this point the 
shape of the canal is uniform as far as the sluice at the sea-head. 

This profile presents a section 100 feet wide at the low-water mark, 24 
feet deep and 30 feet wide at the bottom. The slope of the banks or 
talus is therefore, on each side, of 35 feet base for 24 feet height, that is 
about 1^ to 1, corresponding to an angle of 32°. This easy slope is more 
than sufficient, with the compact nature of the soil, for the preservation 
of the banks. 

On the right and left of the water-line, a berme 15 feet wide is formed ; 
it serves to receive the falling-in that might occur in the upper levee, 
and also to increase the strength of this levee and consolidate its base. 

On each side of this base rises the levee formed with the earth from 
the canal. It is 10 feet high, and consequently meets the upper level of 
the lateral walls, the brick-work of which is 34 feet above the bottom of 
the canal. The width of the levee at its top is 15 feet, and for its greater 
solidity it will have 60 feet at its base; it is a slope of 49, corresponding 
to an angle of 20°. 

On the lower levee (in relation to the river) the railroad for the tow- 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 89 


age of the ships is built. Two turning-tables, situated at the two ex¬ 
tremities ot the line, permit the direction of the locomotive to be 
changed. 

From the middle sluice the canal runs a distance of 13,880 feet in 
main-land on a level. It is a prairie, cut in the last mile by a few unim¬ 
portant lagoons. It crosses then the large bay on a width of 5,GOO feet. 
It is during this passage that it spreads out in the basin that we have 
mentioned. This basin will be used as a wet-dock for the dredging- 
machines for the boats employed in the service of the canal, and for 
the vessels which, for some reason, would need to stop on their way. 
Coming out ot the bay the canal runs 4,000 feet through a prairie ; it 
runs again into a series of lagoons of 3,000 feet, gains land once more 
for a distance of 2,600 feet, and finally crosses a last bay of 1,900 feet to 
arrive at Pavilion Island, which it cuts upon a length of 400 feet. 

It is ou the outer shore of this island—that which faces the sea—that 
the pile of masonry intended to contain the seaward sluice is constructed. 
There, also, will be the house of the keeper of the sluice. 

The two arms of the lateral embankments of the sluice on the sea-side, 
form the head of the double pier, which starts from this island in the 
direction of the axis of the canal for a distance of 3,000 feet, where the 
depth of 24 feet at low water is found. These two piers, between which 
it will be necessary to excavate the batture, are the only works of art 
in the canal. And this work can only be looked upon as a feeble 
specimen of analogous structures conceived and executed by modern 
science. Thus the dike of Cherbourg has 11,300 feet of length, in 
depths of 44 feet of water. 

The pier of Plymouth has over 4,000 feet in 34 feet of water. The 
dike in the Bay of Delaware has 3,600 feet in a depth of 42 feet; that 
destined to form the port of Peluse, for the entrance to the Suez Canal, 
will have 18,000 feet of development until it attains a depth of 24 feet. 

The south pier on which the railroad will be budt, will terminate at 
its end by a large mole of 100 feet diameter, in the center of which will 
be placed a light house with lenticular apparatus. 

The description gives a complete idea of the canal. We have now to 
show how the depth of 24 feet which we have given it cannot be subject 
to any change, either in increase or decrease. 

The increase in the depth would have the inconvenience of under¬ 
mining the foundations of the masonry or the base of the embankments 
and produce a caving in. This danger is not to be feared on the river¬ 
side. It will be seen that its waters scarcely penetrate in the canal; it 
could, therefore,fonly exist from the sea-side; but, when the sea threat¬ 
ens, the outer lock is immediately closed and the whole channel is as 
smooth as a pond. As to the bottom of the lengthening of 3,000 feet 
situated between the two piers, its depth and its shelter are such that 
the sea will remain smooth there at all seasons. 

There remains the otherwise dreadful danger of a reduction in the 
depth; that is, a reduction in the 24 feet depth originally given to the 
canal. Then, again, the cause would exist either in a bar formed at the 
entrance of the canal in the sea, or in alluvions deposited by the waters 
of the river. As regards the sea we have seen that the canal opens on 
the west pass of Breton Island, at a point where the waters of the 
Gulf becoming compressed increase in speed, and rather tend to deepen 
their bed instead of filling it. This circumstance is sufficient to prove 
that the sea, instead of forming a bar at the entrance of the canal, 
would, if a foreign agency created one there, take it crosswise and 
sweep it offi 


90 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Can we feel as secure on the river-side? The waters as they enter 
the lock bring at each sluice-full a volume of 14,400 cubic feet, repre¬ 
senting about 85 cubic feet of earth. It is apparent that with twelve 
sluiee-fulls per day, the progressive filling up of the canal might be 
feared, but a very simple disposition, sanctioned by experience, enables 
us to avoid this inconvenience. A gate made in the center of the lat¬ 
erals forms the opening to a vault which crosses the thickness of this 
mason-work and opens on a discharging canal. The sill of this door 
or gate is on a level with the water-line of the canal, and it is closed 
when the waters of the river enter the lock. So soon as the level is 
established between the lock and the river, and when the ships have 
passed from the river into the lock, instead of opening the gates of the 
middle sluice, this lateral gate is opened; the river-water, which, from 
its lesser density, has in great part floated upon the salt water, runs 
out by this outlet, and the gates of the middle sluice are only opened 
when the level has come down to the water-line. By this means the 
waters of the river only penetrate into the channel in very trifling 
quantity. 

Besides, if any accretion were formed in the channel or in the locks 
on the river side, it would be sufficient to take advantage of the season 
when the river being at a low-water mark and the sea at high water, 
(the level of the latter is a few feet higher than the former,) to use this 
difference of level for sweeping off of all deposits that might have 
accrued. 

As to the accretions we might suppose would exist in the river at the 
entrance of the head sluice, the study of the river’s course has proved 
that, from its natural regimen, they are not to be feared, the accretions 
forming themselves on the opposite bank. 

. Thus, all the objections that might be raised against the opening of 
an artificial outlet to the Mississippi have been met. The circumstances 
in which we execute it must free us forever of all fear that those 
two great obstructors of the passes, the Mississippi and the sea, could 
inspire. 


EXPENSES AND REVENUES OF THE CANAL. 

The estimation of the cost of the canal and its revenues is subdivided 
in several chapters, which may be recapitulated under the following 
titles: 

1. Value and supply of the materials. 

2. Order and direction of the works. 

3. Value of the works. 

4. Means of execution. 

5. Revenues of the canal. 

1 .— Value and supply of the materials. 

The necessary materials are wood, granite, iron, cast iron, brick, 
lime, sand, pozzolana, shells, and fuel. 

Examining, according to the rules of engineering, the resources pre¬ 
sented by the locality, we must be surprised to find so many assembled 
on this spot. Excepting granite and iron, we find all the other materials 
on the spot and in a very limited space. 

Wood.— It is well known that the coasts of the Mississippi are one of 
the greatest markets for pine and cypress lumber. For more than half 
a century France and England have been receiving cargoes of lumber 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 91 

shipped from Ship Island and Pensacola. Now these two points are 
only distant, one sixty miles and the other one hundred and twenty miles 
from the canal. All the pine and cypress needed will, therefore, reach 
us by a direct line of navigation. 

The pine logs for the piles will come at $5 per thousand feet, deliv¬ 
ered ; the same sold as worked timber will not cost over $10 per thou¬ 
sand feet; two-inch pine boards will be worth $11. 

The cypress timber will come at $25; the cross-ties for the railroad 
will cost 75 cents apiece. 

Oak timber brought from Saint Louis, by the way of the river, may 
be calculated at $35. 

Iron and castings.— Iron will only be used for smith’s work, and to 
strengthen joints. It is an important matter in our calculations. It may 
be valued at 7 cents per pound, and at 4 cents—all delivered. The cast- 
iron will be used principally for the railroad, and will cost $35 per 
thousand pounds. 

Granite. —The granite will be shipped from Boston, bored to order; 
it will cost $1.25 per cubic foot. 

Bricks.— No better earth for the manufacture of bricks can be found 
than that coming from the excavations of the canal itself. They will 
be made on the spot at a cost of $7 per thousand. 

Lime. —We have mentioned an island near Fort Saint Philip, called 
“ L’ile a Ooquilles,” (Shell Island.) It is a large mound furnishing all the 
material for the manufacture on a large scale. This lime can be made 
at a cost of 75 cents per barrel. 

Pozzolana. —The marly clay of which we have spoken will furnish 
the artificial pozzolana intended to change the common shell-lime into 
hydraulic lime. It may be valued at 50 cents. 

Sands, shells, clay. —These materials, which are to be found on 
the spot, have no other value than that of the necessary labor to gather 
them. We will set them at 10 cents per barrel. 

Fuel.— The only cost of fuel will be the labor and transportation from 
the banks of the river to the spot where it will be used. The inex¬ 
haustible quantity of drift-wood on the river furnishes logs, which the 
inhabitants on that coast have split, and sell as cord-wood to the 
steamboats. This wood may be valued at $2 per cord. 

Order and direction of the tvorlc. 

In order that the following estimate may be understood without an 
examination of the detailed plan of the canal, it is proper to indicate 
how the works will be organized and how conducted, so as to be com¬ 
pleted in the space of two years. 

The lines of axis and outlines being marked on the ground, a gang 
of ditchers will dig up all the cube of earth on the bank of the river 
that exceeds the levels of its waters. Then, two dredging-machines of 
35 horse power, and capable of excavating the depth of 12 feet, will 
commence at the bank of the river ; they will clear all that space to be 
occupied by the lock and its sluices, leaving to the sides of this lump 
the necessary talus to prevent the caving in. 

This lump once cleared, one of the machines will dig on the axis of 
the canal a passage of 50 feet, and, after following the passage for a dis¬ 
tance of 200 feet, it will place itself crosswise and will begin the exca¬ 
vation of the channel on one of its banks. I lie other machine, passing 
by the same road, will turn in the opposite direction from the firsthand 
will commence with the channel on its other bank. 4hey will continue 


92 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

this operation indefinitely. Behind them a drege-boat of 50 horse¬ 
power will proceed to the final excavation, to the total depth ot 24 leet. 
During this time three pile-driving boats will begin driving the neces¬ 
sary piles for the formation of a dike in the river, intended to inclose 
in front the space of the lock. Another of these boats will drive the 
piles of the dike at the end of the space where the dredge-boats will 
have entered the channel. 

When the dikes will have been completed, a draining-machine of 30 
horse power will empty completely the space and maintain it perfectly 
dry. Then will begin the driving of the piles for the construction of 
the first floor. A trellis-work will be placed on these piles, and the 
hollows filled with beton. The trellis will be covered with a floor, on 
both sides of which will begin the lateral walls of the lock. A second 
trellis-work, with a band under each counterfort, will extend the whole 
length of the lock between the lateral walls, and will receive the double 
flooring of frame. 

The mason-work of the lateral walls will be 34 feet high, 12 feet 
thick at the top and 24 at the base. It will be buttressed on the land- 
side by 22 counterforts of same thickness. The outside facings of the 
lateral walls will be of granite, the interior masonry of bricks laid in 
hydraulic cement. 

While, on the river side, the excavating of the channel and the con¬ 
struction of the lock will be carried on, the same operations will be 
performed on the sea side. 

A dredge of 50 horse-power, with capacity to excavate 24 feet, will 
begin the excavation from the deep-sea side, going toward Pavillion 
Island, on a line with the axis of the canal. When it will have exca¬ 
vated the space to be occupied by the mole and by the two heads of 
the pier, two pile-driving boats will come and drive the piles, by means 
of which will be constructed two dikes, one for the head of the north 
pier, the other for the head of the south pier with the mole attached. 

When it will have reached a 42-foot depth, the 50 foot horse power 
dredge will be replaced by another of 35 horse-power, which will con¬ 
tinue the channel between the two piers of the necessary width not 
only for the channel, but also for the foundations of the piers; it will 
work this way as far as Pavilion Island. Then begins the same kind 
of work as at the river-head, to wit, excavatiug of the lump for the sea¬ 
side sluice, lengthening of a passage 50 feet, to introduce the dredge- 
boat in the line of the channel, the excavation of which will be done by 
this boat until it will have met the two other boats coming from the 
river end. 

Meanwhile, two dikes, one on the sea, the other in the 50-foot passage, 
will inclose the lump intended to receive the sluice on the sea-side. 

When it will have completely inclosed, the dmining-machine will 
drain it, and the pile driving, trellis-frame, beton filling, laying of the 
flooring and frame-work, will be constructed in the manner already ex¬ 
plained. The masonry will be made in the same style and proportions, 
with granite facings, like all the other exterior facings of the construc¬ 
tions of the canal. 

The piers and mole will have been constructed in the mean time, and 
these works are carried on simultaneously. 

The mole is a pile of brick-work (it could be constructed of beton) 
forming an annular cylindrical mass, whose interior hollow is of 72 feet, 
and the thickness of the ring of 42 feet. It is coated outwardly with 
granite on all its circumference, and its upper platform is also of granite. 

Finally, the piers can be undertaken independent of the other works. 



IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. ( ,)S 


The first operation will be to sink in the channel comprised between 
their two sides, and in all the space they occupy, a flooring intended to 
level the bed excavated by the dredges, and to connect the two piers by 
a common base. 

This flooring, the bottom of which is full and the upper part formed 
by a trellis tilled with beton, will be sunk to the bottom by panels of 
25 feet; once leveled by means of concrete blocks of beton having 4 feet 
height, 24 feet in the direction perpendicular to the axis, and 10 feet 
parallel thereto, will be sunk at 50 feet distance on the right and left of 
the axis of the canal. These blocks are hollow, and their sides are one 
foot thick j they may, if necessary, and for the better strengthening, be 
filled with earth. The face of the canal is slightly inclined. The two 
upper layers will only have 22 feet, offering a decrease of 2 feet on the 
sea side ; this graded deduction will extend to the water-line, where the 
length of the blocks will only be of 18 feet. The 10 feet of pier from 
the water line to the level of the lateral walls of the sluice will be con¬ 
structed of bricks. 

In short, it will be seen that all the different points of the works may 
be begun simultaneously, and there is no impediment to the forming of 
six or seven gangs, except the assembling of so many workmen on the 
same spot, the difficulty of superintending such a large number, the dif¬ 
ficulty of supplying materials, the incumbrance caused by the arrivals, 
and other obstacles that will l>e understood by practical men. It is well 
understood that the order of the works may be modified according to 
circumstances. 

We will pass now to the estimate of the cost of each part of this great 
enterprise. 

Value of the icorhs. 

Section 1.—Head-sluices and locks on the river: 

Dikes .. $2, 700 

Excavating and draining. 29,917 

Pile-driving, trellising, and filling with beton . 12,324 

General flooring and frame-work . 13, 810 

Masonry, bricks, and granite.. 184,170 

Puddling anti leveling the rubbish. 8, 700 

Sluice-gates and accessories.. -. 8, 000 

-$259,621 

Section 2.—Channel and embankments: 

We must set forth here the data which have served us as 
a basis for the estimates at this important part of the work. 

.After a long discussion of the analogous works performed in 
the ports of Toulon and Valence, on the Seine, and on the 
bars of the INile, the engineers of the Suez Canal have adopted 
machines that not only perform the excavating, but also, by 
means of revolving carriers, transfer the rubbish on the bank. 

These machines, of 35 horse power, working 250 days per 
year, can excavate 375,000 cubic yards, at an average cost of 
20 cents.' The 50 horse power engines will work at the rate 
of 30 cents per cubic yard. The work of the opening of the 
channel is to be done, as stated, in prairie land for a distance 
of 21,580 feet, and in lagoons for 10,500 feet, on an average 
depth of 2 feet. During all this passage through the lagoons 
it is necessary to form, on each side of the canal, a casing 
made of piles and boards, rising to the height of 3 feet above 
high-water mark, and preventing the sea from washing off 









94 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


the rubbish that is to form the banquettes and levee. This 
work is necessary in order to allow the levee to settle and 
consolidate. 

The digging through prairie land will cost.$300,140 

Through lagoons comprising the basin. 121, 506 

The wood-work in the lagoons. - - 16, 848 

The making of the levees, both in prairies and 

lagoons... 182, 004 

-$620,588 

We cannot pass silently the result of the calculation of 
iilling as compared with the excavating. We had indicated, 
as a basis perfectly sufficient for the solidity of the levee, 
a length of 600 feet; that is, 224 feet of base on each side, 
for a height of 10 feet; but the disposable rubbish will en¬ 
able us, while leaving the slope on the canal side, to extend 
the base on the outer side as far as 120 feet from the ban¬ 
quette, which will give a nearly horizontal talus, and relieves 
us of all fears of the action of the sea, even in the hurricanes. 

Section 3. —Seaside sluice, (excavating already comprised 


in the preceding chapter:) 

Dikes and drainage. $3,164 

Piles, trellis, and beton work.-. 7, 008 

General flooring and frame-work.. .. 5,153 

- Masonry, bricks, and granite. 55,302 

Puddling and leveling the rubbish... .. 2, 040 

Sluice-gates and accessories.. 4, 000 

- 76,667 

Section 4.—Piers and mole: 

Piers .—Excavating and leveling rubbish.. $107, 584 

Inferior flooring and concrete filling. 151, 124 

Temporary wood-work for construction of 

piers. 45, 000 

Masonry, concrete works, bricks, granite 
heads of 200feet, both inside and outside, 

say 800 feet. 646,107 

Mole .—Masonry and filling, granite facings., . 50,188 


Section 5. —Accessory works and appendages : 

Temporary building for the workmen, diving-bell, 
pumps, and fresh-water ditch, warehouse, work¬ 
shop . $20,000 

Draining-machine of 30 horse power, placed on a 

boat .....'. 8,000 

Six boats for driving piles, at $1,600 each. 9, 600 

Three dredge-boats, of 35 horse power, $ 12,000each. 36, 000 
Two dredge-boats, of 50 horse power, $18,000 each.. 36, 000 

Cost of tools and instruments, at 10 per cent, on first 

cost.. 30, 000 

Single-track railroad and accessories. 70,000 

Two locomotives. 20, 000 

Sundry buildings, administrator’s house, lock-tend¬ 
ers’ houses, stores, depots, workshop for the 
machinery, &c. 35,000 


264, 600 































IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 95 


Tlie capital strictly necessary, resulting from what precedes, 

must therefore be of. ..$2,221, 5G9 

But it would not be prudent, in hydraulic calculations, to 
place unlimited confidence in an estimate. In order to meet 
all omissions and unexpected casualties, it is wise to add 1-5 
of the total amount, say. . 444, 313 

Which brings the total at. 2,005,882 

If we look back to the topographical description of the country given 
by. us, it will be remembered that the canal crosses a region of low lands 
where the sea brings her alluvions, and which she sometimes destroys 
during her storm. The double dike of the canal, six miles in length, 
will break the efforts of the sea, and annul its swiftness in that section. 
The result will be that the lagoons will become real basins of precipita¬ 
tion, the bays will become lagoons, to be filled up in their turn, and the 
water will recede forever, letting a new continent rise. 

A few years will be sufficient, even if we consider only the actual 
rapidity of the increase, to connect permanently and securely to the con¬ 
tinent of the left bank of the river this archipelago now filled and lev¬ 
eled. Thereafter a belt levee, similar to that of the canal, is all that 
will be needed to protect this new soil from the inroads of the Gulf. 

The river levee protecting it on the other side from the overflows of 
the Mississippi, we will have conquered from the sea a piece of land of 
nearly triangular shape, having six miles for the height of the triangle 
and about fifteen miles at its base, that is to say, a surface of about 
forty-five square miles. This surface, perfectly plane, formed of argillo- 
siliceous alluvions, would probably be suited to all sorts of cultivation, 
admirably developed by the salted atmosphere, so soon as the soil would 
have been properly reclaimed from its saline conditions by periodical 
overflows of fresh water, regulated by means of sluices constructed in 
the levee of the river. 

B. MONTA1GU. 


D. 

[Maps not printed.] 


2 . 

REPORT OF BOARD OF ENGINEERS UPON CAPTAIN HOWELL’S PROJECT 

FOR A SHIP-CANAL CONNECTING THE MISSISSIPPI RIVER WITH THE 

GULF OF MEXICO. 

The board of engineers constituted by Special Orders >To. 83, dated 
Headquarters Corps of Engineers, Washington, D. 0., June 30,1873, to 
consider and report upon the plan submitted by Capt. C. W. Howell, 
Corps of Engineers, for a ship-canal to connect the Mississippi Biver 
with the Gulf of Mexico, in the navigable waters thereof, made in com¬ 
pliance with a resolution of the House of Bepresentatives, passed March 
14, 1871, have the honor to submit this report. 

The resolution referred to is as follows, viz: 

Resolved, That the Secretary of War be, and is hereby, requested to cause an exam¬ 
ination and survey, with plans and estimates of cost, to be made by an officer of engi¬ 
neers, for a ship-caual to connect the Mississippi River with the Gulf of Mexico, or the 
navigable waters thereof, of suitable location and dimensions for military, naval, and 
commercial purposes, and that he report upon the feasibility of the same to the House 
of Representatives. 








96 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Iu compliance with the foregoing order, the board met in the city of 
New York on the 25th day of last July, and held a number of meetings 
during that mouth, and subsequently thereto, as shown by the minutes 
of proceedings transmitted herewith. 

At these several meetings there were examined and discussed not 
only Captain Howell’s project for the Fort Saint Philip ship canal, as 
set forth in considerable detail in his report of February 14, 1873, and 
the accompanying charts and plans, but descriptions of and reports upon 
similar works successfully executed by European engineers. 

It being deemed expedient, before giving a formal expression to their 
opinions, to visit and examine the site of the proposed canal, as well as 
to obtain the views of local engineers upon the subject under considera¬ 
tion, the board adjourned to meet in New Orleans. 

The board accordingly re assembled in that city on the 24th day of 
last November, and on the 25th proceeded down the Mississippi River, 
viewed the proposed location of the canal, and visited Forts Jackson 
and Saint Philip, both heavy structures, resting on an alluvial forma¬ 
tion in all respects similar to that through and upon which the canal 
would have to be constructed. 

The Southwest Pass was also visited, and the working of the dredge- 
boat at Pass a Loutre witnessed. 

The opinions of distinguished local engineers were subsequently so¬ 
licited, and those submitted in writing are attached to this report. 

The views of prominent citizens of New Orleans interested in the 
commercial welfare of the Mississippi Valley were also obtained. They 
are fairly set forth in an article published in the New Orleans Daily 
Times, hereunto appended. 

The conclusions formed by the board may be briefly stated as follows, 
viz: 

1. From the facts and data presented in official reports and other¬ 
wise, from the experience gained on works of the same character, 
and the many improvements made in the practice of hydraulic engi¬ 
neering within the last twenty-five years, but, more particularly and per¬ 
tinently, from the character of the borings made by Captain Howell 
upon the Fort Saint Philip Peninsula, across which the proposed canal 
is to run, the board is of the opinion that no extraordinary engineering 
difficulties in the construction and maintenance of the canal need be 
apprehended. But it is suggested, in order to avoid beds and pockets 
of quicksand known to exist at some points in this locality, that the 
precise line of the canal should not be decided upon until a more 
thorough examination of the substrata has been made by borings. It 
is not improbable that such an examination may indicate the expedi¬ 
ency, and perhaps the necessity, not only of adopting a curve, or a series 
of curves, in preference to a straight liue for the axis of the canal, but 
also of selecting other points of termini than those recommended by 
Captain Howell. 

Indeed, one member of the board is in favor of locating the Gulf ter¬ 
minus to the northward, and consequently under the lee of Sable 
Point, and of securing the requisite depth of water into Isle au Breton 
Pass by dredging. This would naturally carry the river termiuus 
nearer to Fort Saint Philip, and perhaps within suitable distance from 
the work to satisfy the requirements of a good defense without the 
erection of special works for that purpose. The question of affording 
adequate military protection to the outer end of the canal forcibly sug¬ 
gests the head of Isle au Breton Pass, north of Sable Point, as the 
proper point of outlet, for the reason that suitable defensive works can 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 97 


be established there at less cost than at any other point. Bat all those 
questions are deemed essentially subordinate. They must, of necessity, 
yield to the paramount consideration of adopting that locality for the 
canal which shall best secure the requisite stability for the sides and 
bottom of the prism and the foundations of the locks. 

-• With regard to the plan submitted by the engineer in charge, he 
has stated that it was prepared while he was pressed with other important 
duties, and that, under the circumstances, it was not possible to perfect 
all details ot the project, or to make the numerous borings which are 
considered a necessary preliminary to a precise location of the route of 
the canal throughout its entire length. The estimate submitted can 
therefore only be regarded as an approximation to the probable cost of 
the work. 

3. The board approve the debouche of the canal into the Gulf waters 
of Isle an Breton Pass upon the ground that the advantages possessed 
by these waters of ample and permanent depth, and good and capacious 
anchorage-grounds, are not only adequate to the objects in view, but 
are greatly superior to those which obtain in any other locality. A com¬ 
parison of old charts with those that are more recent, both verified by 
Captain Howell’s survey, shows quite conclusively that the depth of 
water in this pass, as well as upon the bar at its opening into the Gulf, 
is quite permanent; and the board coincide with Captain Howell’s views 
that existing circumstances promise a continuance of deep water in this 
pass. 

4. The board also approve the location of the inner end of the canal 
upon the straight portion of the Mississippi River below Fort Saint Philip, 
at such distance from that work as the final examination and borings 
shall indicate as most suitable, due weight being given to the question 
of providing adequate military protection for the work from existing 
fortifications, or otherwise, as may be found most advantageous. 

[For a description of the canal, in order to understand the modifica¬ 
tions recommended, reference may be made to Captain Howell’s report, 
and the accompanying plaus, herewith returned.J 

5 4- Captain Howell’s project for the construction of the lift-lock con¬ 
templates a coffer-dam surrounding the entire lock. The board enter¬ 
tain doubts of the practicability of this method of construction at a 
reasonable cost, owing to the nature of the sod and the engineering 
difficulties consequent thereon. 

In view of this circumstance, and upon a suggestion made by the 
senior officer of the board, it is believed the apprehended difficulties 
may be avoided by replacing the side walls of the lift-lock chamber 
with gentle slopes of earth, and constructing the upper and lower lock- 
gates, with their foundations and side walls, separate from each other. 
With these changes the foundations of the ends of the lock can be laid 
by any one of the several processes well known to engineers. The bot¬ 
tom and sides of the lock-chamber should be revetted as far as neces¬ 
sary. 

6. The following modifications of the proposed dimensions of the 
canal are recommended: 

Length of lock-chamber increased to 500 feet. 

Width of lock at the gates reduced to 00 to 05 feet. 

Depth over sill, at extreme low water in the Gulf of Mexico, reduced 
to 25 feet. 

Depth of trunk of canal, at extreme low water in Gulf, (not changed,) 
27 feet. 

Width of canal at bottom, (not changed,) 200 feet. 

H. Ex. 220-7 



98 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Sides of canal to slope about 1 upon 4. 

A suitable arrangement of sluices must be made to meet these pro¬ 
posed changes. 

The foundation and construction of the guard-lock may be the same 
as for one of the gates of the lift-lock. 

7. The jettees, extending the canal into the deep waters of Isle an 
Breton Pass, will doubtless require more material than the plan sub¬ 
mitted by Captain Howell contemplates; but inasmuch as the length of 
these jettees and their cubic contents depend, to no inconsiderable ex¬ 
tent, upon the position selected for them, no very accurate estimate of 
their cost can be made until the final location is determined upon. 

8. It is evident from the foregoing that the necessary and unavoidable 
absence of sufficient data to determine the best location for the line of 
the canal across the peninsula, including its termini, and particularly 
its debouche by jettees into Isle au Breton, renders it impossible to make 
a close estimate of its cost. 

A new estimate, resulting in part from a revision of that made by 
Captain Howell, has been rendered specially necessary in view of the 
modifications of plan recommended by the board. It is believed to be 
ample to coA r er the cost of constructing a canal of the dimensions given 
above, located within the limits designated. The estimate amounts to 
$10,273,000. 

The subject of the improvement of the passes at the mouths of the 
Mississippi will be separately presented. 

Bespectfully submitted. 

New York, January 9, 1874. 

JOHN NEWTON, 

Lieut. Col. Engineers , Bvt. Maj. Gen., U. 8. A. 

Q. A. G1LLMOKE, 

Maj. Engineers, Bvt. Maj. Gen.. U. 8. A. 

G. K. WARREN, 

Maj. Engineers , Bvt. Maj. Gen., TJ. 8. A. 

WM. P. CRAIGHILL, 

Maj. Engineers , Bvt. Lieut. Col., TJ. 8. A. 

G. WEITZEL, 

Maj. Engineers , Bvt. Maj. Gen., TJ. 8. A. 

C. W. HOWELL, 

Capt. Engineers, Bvt. Maj., TJ. 8. A. 

Not fully concurring, my views will be presented in a separate report. 

J. G. BARNARD, 

Col. Engineers, and Bvt. Maj. Gen., TJ. 8. A. 


3. 


New York, January 20, 1874. 

General : Having dissented from the views of the majority of the 
board of engineers convened by Special Orders No. 83, June 30, 1873, 
to consider and report upon the plan submitted by Capt. C. W. Howell, 
Corps of Engineers, for a ship-canal to connect the Mississippi River 
with the Gulf of Mexico, I state, at the outset, that, in making sepa¬ 
rate reports upon the particular “ plan ” submitted, and upon the al¬ 
ternative of the “ improvement of the passes,” my object will be to 
prove— 



IMPROVEMENT OF MOUTII OF THE MISSISSIPPI RIVER. 99 


1st. That (mummy that a canal is to be made, the plan now sub¬ 
mitted suffices only to show that a more protracted and more compre¬ 
hensive study is required to fix the location and determine the general 
details of construction, and to make an estimate which can rightly be 
con sidered approxim ate. 

2d. That before resorting to an artificial work of the difficult and 
costly character of a u ship-canal,” a more attentive consideration of 
the superior advantages of the natural mouths, and of the fair proba¬ 
bility of utilizing them, is needed. 

Furthermore, I add, that neither difficulties nor costs are to be 
weighed against the demand for an adequate navigable outlet to the 
Mississippi Fiver, whether that outlet be a canal or otherwise; but the 
u whether” here becomes, as I think I shall show, the symbol of a ques¬ 
tion not yet solved in favor of the canal. % 

The first proposer of a ship-canal appears to have 1 been Mr. Benja¬ 
min Buisson, who, in 1832, suggested that a canal u six and a half miles 
long, commencing on the left bank of the river, a few miles below Fort 
Saint Philip, and entering the sea about four miles south of Breton 
Island, would afford an easy and safe access to the river to vessels draw¬ 
ing 20 feet.” Subsequently, Lieut. B. Poole, a graduate of the Military 
Academy, serving as topographical engineer, surveyed (or, more accu¬ 
rately speaking, reconnoitered) this route, and reports (1837) that a canal 
here “ offers a fairer prospect of opening the Mississippi to ships of the 
largest class than any other plan that has been spoken of.” 

But it remained for the late Maj. W. H. Chase, of the Corps of 
Engineers, to give the canal project a defined form by projecting in 
an official report dated February 9, 1837, what may be (though without 
drawings) properly styled a plan for u a ship-canal to connect the Mis¬ 
sissippi River with the Gulf of Mexico.” This plan is best exhibited by 
an extract from his report. He says : 


The obstacles presented to an easy entrance of the Mississippi by vessels drawing 12 
feet of water are productive of great injury to the commerce of New Orleans, and 
require to be promptly removed, or , failing to be done , the construction of a ship-canal 
on the plan indicated by Major Buisson should be resorted to. 

By reference to chart, the line of the proposed canal is exhibited, commencing at a 
point about two and a half miles below Fort Jackson, and extending seven miles to 
the shores of the Gulf, and thence, by a jetteo 1,760 yards, to 30 feet water. It is 
proposed to carry into effect this plan of a ship-canal— 

I. By a construction of a guard-lock at the junction of the canal with the river. 
The object is to prevent the flowing of the river into the canal. ^ 

II. The excavation of the trunk of the canal, 100 feet wide at top, 30 feet wide at 
bottom, and 30 feet deep. The object of such large dimensions is at once to provide 
not only for the entrance of the largest ships engaged in commerce, but also of ships 
of war of the largest class. The advantages offering for both classes of vessels are 
obvious, and need no comment. 

III. The construction of the jettees or breakwaters of large dimensions, having for 
their base 100 feet, with a depth varying from 5 to 30 feet, and 20 feet wide at top, and 
raised to the level of high water. 

The practicability of this plan depends solely on the question whether a lock of the 
dimensions required for the admission of the largest-sized vessels can be constructed on 
the banks of the Mississippi. 1 think the question may beeasily answered in the affirm¬ 
ative, for we can refer to the practicability of excavating almost to any depth in the 
mud of the Mississippi Delta as exhibited at various works constructed by the United 
States, and by individual enterprise. At Fort Jackson, on the Mississippi River, the 
foundations were excavated to the depth of 12 feet, and were kept free from water by 
means of a small engine attached to pumps of considerable power. 

The operations at Fork Jackson came frequently under my observation, and I amlefk 
in no doubt as t > the perfect practicability of excavating to the depth of 30 feet, and also 
of the practicability of establishing a solid foundation by piling for the support of the 
walls of masonry necessary for the construction of a lock. 

Taking for granted, therefore, that a lock can be constructed, wehave only to consider 
the means of excavating the trunk of the canal and the construction of ashore break- 


100 IMPROVEMENT OF MOUTII OF THE MISSISSIPPI RIVER. 

water. The marsh lying between the river and the Gulf, through which the line of 
the canal is located, is intersected by several bayous, all of shallow depth of water. 
Commencing at the river, it is proposed to excavate to a depth of 6 feet, affording suffi¬ 
cient water for the dredging-machine, which will thereafter be employed in the exca¬ 
vations, the canal being excavated to a depth of 6 feet through its extent. 

The estimate was for a lock 200 feet long, 50 feet wide, and 30 draught, 
of masonry, founded on 1,000 piles, a canal trunk 30,960 feet long, 30 
feet wide at bottom, and 100 feet at top, and 30 feet deep, and two jet- 
tees, each one mile long, 1,000 feet apart, of dimensions already men¬ 
tioned. A guard-lock at the sea-end does not seem to have been pro¬ 
vided for. Major Chase’s estimate for workmanship was $8,019,299, in¬ 
creased to $10,000,000, to cover superintendence contingencies. 

Twenty years later, R. Montaign, civil engineer, elaborated a plan, 
with considerable detail, for a canal on this identical location, with a 
masonry lift-lock 400 by 80, with 24 feet draught at low water, founded 
by means of coffer-dam on piles and grillage, a canal trunk six miles 
long, of identical dimensions, with “ piers and moles ” of peculiar con¬ 
struction, all of which he estimated to cost $2,005,882. 

At the suggestion of Major Chase, the line of the projected canal was 
embraced by Captain Talcott in his great survey of 1838. “ It resulted,” 

says the latter, “ in showing a tine ship-canal leading up to where he 
proposed it should debouch, and the perforation of the ground to a 
depth of 40 feet indicated a firm bottom of sand mixed with mud, tena¬ 
cious of water, and altogether such as would be considered favorable 
for excavatiug, and on which there would be no difficulty in securing a 
foundation for locks or structures of any kind.” 

This canal project was reviewed by the late Chief of Topographical 
Engineers, Col. J. J. Abert, in his annual report, December, 1839. After 
some remarks on the “ difficulty of making the excavation and keeping 
it free in this soft soil,” he states thatthe execution of the locks “ would 
constitute no insurmountable difficulty if this botton ” ( i. e ., the “ firm 
bottom of sand and mud” found by Captain Talcott) “ was adequate to 
sustain the locks.” 

These are the only points he makes concerning engineering difficul¬ 
ties. But he goes on to say that the plan “ would require a break¬ 
water to protect the shipping in the bay between Sable Island and Isle 
au Breton from eastern weather;” and again, thatthe plan “issubject 
to a very weighty objection, independent of considerations in reference 
to the construction, which is, that it would be exposed to the efforts of 
an enemy, and would involve the Government in enormous expense for 
its protection. This consideration would, in my (his) judgment, justify 
the Government in its rejection, and would turn all its views back to 
the previously exposed methods of improving some one of the passes of 
the river.” (Colonel Abert’s report, 1839.) 

The location of the canal project now submitted to the board is, to 
all intents and purposes, identically that of Major Chase’s. Yet these 
two considerations, made so prominent by the authority I have quoted, 
have not received any notice whatever in the project before us. The 
only reference to it in the report of the majority of the board is found 
n the following: 

Indeed, one member of the board is in favor of locating the Gulf terminus to the north¬ 
ward, aud consequently under the lee of Sable Point, and of securing the requisite 
depth of water into Isle au Breton Pass by dredging. This would naturally carry the 
river terminus nearer to Fort Saint Philip, aud perhaps within suitable distance of 
that work to satisfy the requirements of a good defense, without the erection of special 
works for that purpose. The question of affording adequate military protection to 
the outer end of the canal forcibly suggests the head of Isle au Breton Pass, north of 
Sable Point, as the proper point of outlet, for the reason that suitable defensive works 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 101 




can be established there at less cost than at any other point. Rut all these questions 
are deemed essentially subordinate. They must of necessity yield to the paramount 
consideration of adopting that locality for the canal which shall best secure the requi¬ 
site stability for the sides and bottom of the prism and the foundations of the locks, 
* * * * and after approving “ the debouch into the Gulf waters 

of Isle au Breton Pass,” &c., “the board also approve the location of the inner 
end of the canal upon the straight portion of the Mississippi River, below Fort Saint 
Philip, at such distance from that work as the final examination and borings shall in¬ 
dicate as most suitable, due weight being given to the question of providing adequate 
military protection for the work from existing fortifications or otherwise, as may be 
found most advantageous.” 

These paragraphs either suggest important changes of location, or 
they do not. From anything experience or borings into the soil has re¬ 
vealed, I do not consider as “paramount,” in determining that location, 
the matters so characterized. There would be grave “ difficulties,” in¬ 
deed, in obtaining “requisite stability for the sides and bottom of the 
prism, and the foundations of the locks,” if, as stated, matters so impor¬ 
tant as the accessibility of the canal entrance in “ eastern weather,” the 
protection of the canal-mouth, and of shipping in the roadstead against 
the violence of waves, and the protection of the canal-works against the 
maritime enemy during war, all absolutely essential and unprovided for 
in the project, are “essentially subordinate” to overcoming such diffi¬ 
culties, or to facility of dealing with them. 

When it is borne in mind that the identical location of four different 
engineers (Captain Howell included) was governed by the “paramount 
consideration,” (and a very sound one by itself ,) of the shortest distance 
from the river to deep-sea water , it is scarcely comprehensible that other 
considerations important enough to be weighed with this become “sub¬ 
ordinate” to difficulties of the ground. If so, the bare practicability 
even of the present location is rendered doubtful. 

Neither observation of, and familiarity with, engineering works in Lou¬ 
isiana, nor the borings made by Captain Howell, suggest to me that any 
material variation of its location will be suggested by further scrutiny of 
the substrata, by boring. My knowledge of the soil, indeed, prompts 
me to affirm that, so far as the “foundations of the locks” are concerned, 
(I do not allude, of course, to abrasion by the river,) the bearing-power 
of the soil is not likely to be found better or worse in one place than 
another. Captain Talcott found at forty feet a “firm bottom of sand 
mixed with mud,”* (clay, probably,) and the borings made by Captain 
Howell, after passing through various mixtures or strata of “blue clay” 
and “sand,” exhibit generally, at about 40 feet, a stratum of indefinite 
depth of blue clay, with little and sometimes no sand. This stratum 
possesses, however, in all probability, no greater “bearing” qualities 
than any of the others. Pure blue clay was found at Fort Livingston, 
(underlying nearly pure and incompressible sand,) at depths of from 
twenty to twenty-five feet. Few works in Louisiana have settled more 
than Fort Livingston, and there are good reas ns for believing that the 
yielding occurred in the clay. Major Turnbull found at the site of the 
New Orleans custom-house, after a few feet (three or four) of light sur¬ 
face-matter, “ stiff blue clay” slightly mixed with very fine sand, extend¬ 
ing to depth of boring, (27 feet,) and yet that custom-house, the walls 
of which rest on grillages 15 feet wide, has settled nearly 2 feet. Forts 
Jackson and Saint Philip rest on higher strata than this 40-foot stratum. 
Their settlement has been great, but not so great as that of Fort Liv¬ 
ingston. 

* I think Captain Talcott meant to say that throughout his forty feet of perforation he 
found saud mixed with mud, (or clay,) which he regarded as “ firm bottom.” 



102 IMPROVEMENT 01 MOUTH OF THE MISSISSIPPI RIVER. 


The strata, therefore, whether superficial or deep, are (so far as we 
know) all equally yielding. The mobility, of the “fine sand,” where it 
exists, as it sometimes does, in strata almost destitute of clay, ma\, in¬ 
deed, enhance the difficulties of making the canal-trunk, and of getting 
through them to reach the lock-foundation, but it is not likely that 'any 
considerable change of location should result. 

The engineering difficulties, therefore, great as they may be, have no 
claim to being “paramount” in the location of this canal 5 they are 
likely to have but trifling influence upon it, and are wholly subordinate 
to the considerations of accessibility —protection of its harbor against the 
sea —protection of its works against the enemy. The late Colonel Abert 
has officially affirmed that the canal, as located in the project before us, 
was not only unprotected in both these relations, but that it would de¬ 
mand works of such expense as to justify the Government in rejecting 
it, and in turning its attention to the improvement of the passes. 

I do not affirm this ; I merely say that the plan which does not treat 
these matters at all is not a sufficiently complete study of the project. 

The first formal suggestion of a very radical change of location of 
the canal came from one of the professional gentlemen whom the board 
consulted in New Orleans—an engineer whose professional life has been 
identified with the military defenses of the delta of the Mississippi 
liivcr, and with the great engineering questions which the control and 
navigation of its waters perennially raise. (See letter of General G. T. 
Beauregard.) “ Its location,” he says, “ on the river should be under 
the protection of the guns of Forts Saint Philip and Jackson, due re¬ 
gard being had to the permanency of the river-bank.” In a draught of 
a report 1 prepared in New Orleans, and communicated to the members 
of the board, I suggested “whether a location from Saint Philip to 
somewhere near Deep-Water Point, and the dredging of a small harbor 
connecting with Breton Bay, (in 10 feet water,) and under the shelter 
of Sable Island, might not be better than bringing the canal direct into 
the bay, where now proposed. Such a harbor would, while tolerably 
sheltered, be much more easily defended against a maritime enemy.” 

The member of the board “in favor of locating the Gulf terminus 
northward, and under the lee of Sable Point, * * * which would 

naturally carry the river terminus nearer to Fort Saint Philip, and per¬ 
haps within suitable distance to satisfy the requirements of a good de¬ 
fense, without the erection of special works for thatpurpose ,” is understood 
to be one of the signers of the majority report. 

The suggestions “ or opinions” above cited all involve radical change 
of location. They come, therefore, from three different sources, two of 
which are members of the board, and the third entitled to great consid¬ 
eration, for reasons already given. But I go further in suggestion. A 
canal starting a few hundred yards below Fort Saint Philip, and taking 
a direction due north, (nearly,) would strike the Gulf waters at two miles 
distance, and the G-foot curve at two miles and three quarters ; thence, 
on a line directly north to Hog Island, three miles distant, the water 
attains depths of 10 to 12 feet. A dredged harbor of the magnitude of 
that of the North Sea Canal (i. e. the dredged portion, say about two- 
thirds of a million superficial yards, or 13G acres) would not be an un¬ 
dertaking of unreasonable magnitude. It would be perfectly sheltered 
from storm-waves, while a dredged channel in water varying from 12 to 
25 feet depth, of about five miles length, would constitute the com¬ 
munication to the deep waters of Breton Island Bay. The experience 
of dredged channels of* approach to Baltimore, 24 feet deep, (ten miles, 
of which five miles is wholly dredged, the rest partially,) and of At- 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 103 


cliafalaya Bay, (twelve miles long, to about eleven feet depth,) prove 
the efficiency of such channels. Instead of six miles of canal, there 
would be but two. Instead of two jettees of a mile length each, of 
which the cost is so formidable an item, there would be but the bulk¬ 
heads (ot masonry, riprap, or otherwise) from the shore-line to edge of 
the dredged harbor. The canal, for its whole length, would be “under 
the protection of the guns of Forts Saint Philip and Jackson.” 

The anchorage of Breton Island Bay would still be as available as 
now. The defense of that anchorage and of the dredged channel ap¬ 
proach suggests the desirableness of a work on Sable Point, but this 
defense is quite another matter from that of the canal itself, though 
rendered essential by its existence. 

It is not necessary for me to affirm that the location and arrangement 
above suggested are better than that of Major Howell, Major Chase, 
and others. I have only to refer to the grave objections to the latter, 
enumerated by the late Chief of Topographical Engineers, to set forth 
substantial reasons for my position that “a more protracted and com¬ 
prehensive study is required to fix the location.” 

In turning now from the matter of location to that of plans of con¬ 
struction, 1 do not know how I can discharge the duty “to consider and 
report upon the plan submitted” to the board without saying that it is 
not one upon which it would be proper to undertake the execution of 
the work, nor one in which the great problems of the canal construction 
are adequately solved. The majority of the board entertain doubts of 
the practicability (at a reasonable cost) of the method of a coffer-dam 
surrounding the entire lock, “owing to the nature of the soil and the 
engineering difficulties consequent thereon.” • But even if the engineer¬ 
ing difficulties be overcome, the foundation proposed is quite inadequate. 
A grillage covering a surface of 112 by 550 feet, (about,) and only 0 feet 
thick, would be perfectly impotent to distribute pressure or to prevent 


distortion and cracking.* 


Furthermore, I am of opinion that no thickness, within practicable lim¬ 
its, of grillage alone , will suffice to keep such a lock free from distortion and 
injurious settlement. This opinion is founded upon the compressible 
character of the clay substratum, (as already explained,) which invaria¬ 
bly yields to superimposed weight, even if very slight. Mere settle¬ 
ment is not necessarily destructive of masonry structures in general, but 
the working of large lock-gates demands not only the most perfect free¬ 
dom from distortion, but the most perfect level. As a simple means of 
escaping the difficulties of a deep construction so extensive, I recom- 
mended the isolated construction of the masonry gate-chambers. But 
for these the maximum stability, only to be attained by the important 
auxiliary of piling, is indispensable.] Piling can be done without en- 


* Simply as a confirmation, (for I did not first base my opinion on an individual 
iustauce, which had passed out of my mind,) I quote the following note, taken four¬ 
teen years age at the Holder, (Holland :) “The new dry-dock is 350 feet long by 90 feet, 
(interior dimensions.) The site was excavated, the water pumped out, (the soil as deep 
as I could see it, which was about to the level of the bottom of the dock-floor, was 
mixed strata of sand and clay,) then a grillage of timbers three yards thick. The struc¬ 
ture had been completed up to two-thirds, perhaps, of its full height. The weight of 
the side-walls had caused a wide longitudinal crack through the middle, the whole 
length of the dock, perhaps an inch or two wide. They had cut out the old lining and 
bottom arch, and were rebuilding it. The brick masonry was well laid, the bricks in¬ 
different, and the mortar not as hard as our cement mortars.’ 7 

tThe plan of Major Chase—and nothing which has succeeded this plan, so boldly and 
sharply defined, has been any advance—contemplated piling ; so did that of his fol¬ 
lower and (probably) imitator, Moutaigu. The locks in the Y of the North Sea Canal, 
resting on strata of similar character, are piled. 



104 IMPROVEMENT OF MOUTH UF THE MISSISSIPPI RIVER. 


countering tbe engineering difficulties of the coffer-dam process, and 
the masonry can be built, and lock-gates hung, whether by the pneu¬ 
matic or some other method more simple and less costly. The lock 
dimensions (of the plan) have been modified by the majority in their 
report, and judiciously, 1 think. 

The jettee construction of the plan is described by the engineer as 
“one of a substantial though temporary character, and must be super¬ 
seded by one of beton, based on the foundation this one will afford.” 

Even if economy of time justify a “temporary” construction, the one 
designed would, I think, prove inadequate, and the enormous expendi¬ 
ture upon the so rapidly perishing timber-work, $1,000,000, could not 
be regarded as judicious. Of course there is no basis afforded for esti¬ 
mating the cost of the permanent jettees with which the work must be 
provided. 

By reference to the project of Major Chase, it will be seen that he 
places his jettees (of a massiveness fully adequate) 1,000 feet apart, 
dredging the whole space between them. This arrangement provides 
for something like a harbor , and although the objection of eastern ex¬ 
posure is so strongly urged by Colonel Abert, the feature cited furnishes 
a palliative not found in the present plan. 

Breton Island Bay is exactly opened to the prevailing storm-winds of 
the Gulf j and should this location be adopted, I think there can be no 
doubt of the necessity of creating, by the arrangement of these jettees, 
(starting from points on shore 1,000 or 1,200 yards distant, and converg¬ 
ing toward the outlet,) a small artificial harbor, as at the entrance to 
the North Sea Canal. 

Thus far, experience in Louisiana offers no example of the cutting of 
a canal to a depth of 25 feet, unless it be, indeed, the occasional river 
“cut-off's,” which excavate to much greater depth. That the “ prism ” 
can be made and maintained I do not doubt, but I do doubt whether 
that result, including the.protection of the sides,* formation of embank¬ 
ments, roadways, &c., will be attained for the total arising from an 
estimate of fifty cents for each cubic yard, within the defined limits of 
the excavated section. I doubt, however, the necessity of a bottom 
width so great as 200 feet.’ The North Sea Canal, three times the length, 
has but 90 feet bottom-width. This dimension is one easily increased 
if experience shows the necessity. 

In conclusion, I would say that while I do not doubt the entire 
“practicability” of the canal construction, I think that the phraseology 
used in the report of the majority, that “no extraordinary engineering 
difficulties need be apprehended,” rather underrates the real difficulties 
to be anticipated. The sinking of the extensive masonry masses to a 
depth of more than 40 feet below the contiguous river surface is some¬ 
thing which has no actual precedent in Louisiana, and demands the 
most careful study before undertaking, and will task the skill of the 
engineer in execution. 

The climate itself, in conjunction with the marshy soil through whicli 
the work is laid, is no ordinary difficulty, unless, indeed, the work be 
suspended for four or five months of the year. The assembling of large 
bodies of men on that site and under that sun, the turning up of 
marsh soil, impregnated with vegetable matter, cannot fail to generate 
their incidental diseases, and cause mortality which may hamper the 
progress, while the fatal epidemic of the country, unaided by such helps, 
would be likely to cause protracted interruptions of the work. 

6 Sailing-vessels will, of course, be towed through the canal. That expense should 
not he imposed upon steam-vessels, which, of large dimensions and draught, are super¬ 
seding sailers for ocean navigation. 





IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 105 


I do not wish to exaggerate in the slightest degree the difficulties and 
costs of the work, nor to deny that, if the navigation and commerce of 
the Mississippi cannot otherwise be adequately provided for, it can be 
made and should be made. 

But if the execution is not to be entered upon regardless of cost and 
blindly as to ultimate requirements, the location must first be fixed 
by a wider range of considerations and study, and the plans (depending, 
of course, upon the location thus fixed) carefully matured after experi¬ 
mental examination of the site by careful comparison of available meth¬ 
ods of overcoming the difficulties the character of the site reveals; and, 
moreover, all that the canal project carries with it as indispensable accesso¬ 
ries must be planned in relation to it and enter into the estimate. For¬ 
tifications are among these indispensable accessories; so will be also 
some breakwater auxiliary or artificial harbor; so will certainly be the 
cost of maintenance . 

deferring to the experience of other canals with locks, (the Erie may 
be cited,) it would not be safe to estimate this maintenance at less per 
annum than 2 per cent, upon the total cost for this canal.* 

I have thus endeavored to prove that the plan submitted to the board 
suffices “ only to show that a more protracted and more comprehensive 
study is required to fix the location and determine the general details of 
construction, and to make an estimate which can rightly be considered 
as approximate .” 

I shall, in another report, maintain that, “ before resorting to an ar¬ 
tificial work of the difficult and costly character of a ship-canal, a 
more attentive consideration of the superior advantages of the natural 
mouths, and of the fair probability of utilizing them, is needed.” 

Respectfully submitted. 

J. G. BARNARD, 

Colonel of Engineers and Brevet Major-General. 

Brig. Gen. A. A. Humphreys, 

Chief of Engineers , l T . S. A., Washington , J). C. 


Army Building, 

New York, January 28, 1874. 

General: I herewith forward two sketches! which I desire to have 
attached to, and made a part of, my report on the “ plan submitted by 
Capt. C. W. Howell, Corps of Engineers, for a ship-canal,” &c. 

No. 1 is intended to illustrate the quotations from the report (1839) of 
the late Col. J. J. Abert, which urges the necessity of shelter to the en¬ 
trance during “eastern weather.” 

No. 2 is intended for reference in reading what is said concerning the 
question of location and of defense by existing fortifications. 

Very respectfully, your most obedient, 

J. G. BARNARD, 

Colonel of Engineers and Brevet Major-General. 

Brig. Gen. A. A. Humphreys, 

Chief of Engineers , U. S. A., Washington , I). C. 


* This estimate is made with full consideration of the fact that there are no embank¬ 
ments, no leakage, and no “puddling” in the proposed canal; the maintenance, &c., 
of fortifications not included. 

\ For sketches see original. 





106 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


4. 

New York, January 13, 1874. 

The board of engineers convened by Special Orders No. 88, headquar¬ 
ters Corps of Engineers, Washington, D. C., dated June 30, 1873, to 
report upon the project of a ship canal to connect the Mississippi River 
with the deep waters of the G-nlf of Mexico, having had the matter re¬ 
ferred to them extended by the following instructions, viz : 


Office of the Chief of Engineers, . 

Washington, D. C., October 3, 1873. 

Sir: In reply to your letter of the ‘24th ultimo, I am directed by the Chief of Engi¬ 
neers to say that it is allowable and desirable to have the views of the board of engineers 
on the question as to the expediency of improving the navigable outlet of the Missis¬ 
sippi, by the Fort Saint Phiiip Canal, as an alternative to, or a simultaneous measure, 
perhaps, with, the improvement of the passes. 

The report of Captain Talcott, of January 30, is in the hands of the copyist, and will 
be furnished you as soon as possible. 

Very respectfully, your obedient servant, 

JOHN G. PARKE, 

Major of Engineers. 

Col. J. G. Barnard, 

Corps of Engineers, Army Building, New Yorlc City. 


have the honor to submit this report: 

The improvement of the passes has usually been discussed in reference 
to the application to them of the jettee system, or of dredging, in con¬ 
junction with each other, or separately, and the board propose to con¬ 
fine their attention to these methods. 

The depth of water over the bar to serve for commercial, naval, and 
military purposes, it is assumed, should be the same as that selected for 
the draught over the miter-sill of the proposed ship-canal, viz, 25 feet 
atjextreme low water of the Gulf. The pass to be improved is assumed 
to be Pass a Loutre; this having been selected by several engineers, 
advocating the improvement of the mouths of the Mississippi, as the 
best adapted to the application of the jettee.system. 

In order to advance the low-water twenty-five-foot curve of the chan¬ 
nel of the pass from the point where this depth ceases to obtain, to the 
bar, it would be necessary to construct parallel jettees, of the same dis¬ 
tance apart as the shore-lines of the pass where the required depth is 
excavated. 

These considerations fix the length of each jettee at about 24,000 feet, 
and the distance apart 2,200 feet. 

The top of the jettees must be held low, not higher than the banks 
from which they extend, because additional height, while adding to their 
cost, would not induce the passage of more water between them so long 
as the banks of the river above are at a lower level. An elevation of 
the jettees above the banks from which they spring would, in fact, en¬ 
danger the latter in the presence of a rise overtopping them, especially 
at the points where the jettees and banks unite. 

The debouch of Pass a Loutre by two mouths makes it necessary to 
close one of them, and this operation is supposed to be performed by 
the north jettee, constructed across the northern mouth. 

An inspection of the map of the pass, to fix in the mind the necessary 
course of the northern jettee, will show that the present direction of the 
running waters will be deflected by this work, which forms a concave 
bend, to receive them, and a considerable scour of the bank must neces¬ 
sarily ensue, causing the foundation of the jettee to be undermined, un¬ 
less effective measures are taken to prevent such catastrophe. 


IMPROVEMENT OF MOUTII OF THE MISSISSIPPI RIVER. 107 


The board are unable at this time to suggest any remedy, except to 
sink the foundations deep enough to be out of reach of these influences. 
As to how great this depth should be to insure safety, the board have 
no certain means of judging, but it may be 25 feet, or even more. 

The closing of the northern mouth, which, following the line of jettee, 
would be a work operating to deflect the present direction of the cur¬ 
rents, and over 7,000 feet in length, is an undertaking of great delicacy, 
the cost of which, in a soil of the character pertaining to this locality, 
might prove to be excessive. Success in this operation is, however, 
necessary to the application of the jettee system to the pass under con¬ 
sideration, and must be sought at whatever cost, in order to accomplish 
the desired improvement of navigation. (Note A.) 

It is important to say that the advance of the jettees, step by step, 
will cause deep holes to form at their extremities, due to the escape of 
the waters as soon as released, and a consequent excavation of the loose 
soil, which will much increase the depth and cost of these works. 

The dislodgment, by the operation of the jettees, of the immense 
quantities of material from the sides and bottom of the channel, would 
bring the scouring force into contact with the interior of the banks and 
shoals, which consist generally of soil inferior in hardness and firm¬ 
ness; and it would be impossible so to fix the limits of this distributing 
action that it might not often reach the jettees themselves. 

The long, low banks and the shoals of the delta do not owe their ex¬ 
istence or permanence to anything inherent in the strength and consist¬ 
ence of the soil composing them—for on these points all testimony 
agrees—but upon the action of the waves and currents, constituting an 
area of equilibrium, in which the particles are deposited and retained. 

But as these forces are not always as to effect, but only periodically, 
in equilibrium, it necessarily follows that changes in the shoals and 
banks are constantly occurring, not enough, indeed, to interfere with 
the general development of the delta, which appears to advance by 
virtue of uniform laws, but quite sufficient to endanger and even destroy 
the most skillfully-designed works. (Note B.) 

This consideration of the unstable and treacherous nature of the 
shoals and banks is necessary in order to fix the mind upon the cost and 
risk as well as upon the disappointment which would likely attend an 
attempt, upon such foundations, to construct works to coerce or control 
the currents of the passes. 

An estimate has been prepared by Captain Howell, engineer in charge 
of the jettees described in this report, supposing them to rest upon the 
natural bottom, without settlement, as follows: 

Fascines and ballast, at $5 per cubic yard. $2, 545,2*20 00 

Riprap stone, $7 per ton. 2,241, 097 00 


Total. 4,780,317 00 

If settlement and the other probabilities enhancing the cost of this 
work, as already discussed, be considered, it appears entirely within 
limits to state that the above estimate should be doubled. 

Assuming that it will take about four years to complete the jettees to 
the present 25-foot curve outside the bar, and estimating the least 
yearly advance of the bar at 250 feet, it would be proper to add to the 
estimate already the cost of 2,000 linear feet, equal to $68,888. 

There is, besides, the estimate for future annual extensions to keep 
pace with an increased advance of the bar, which by the same authority 
would be $1,013 per linear foot of jettee. 

The next step in order is to consider the effects of these jettees, sup- 






108 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


posed to terminate at the curve of 25 feet outside the bar, upon the 
depth of water in the channel and upon tbe bar; and it will be first 
supposed that the jettees, if projected too for apart, should near the 
bar be brought together sufficiently close to insure the desired scouring 
effect upon the bar. 

Would this state of things, thus produced, endure for a considerable 
time, or for a period sufficient to fill up the deep space ahead in the 
Gulf to a distance equal to the present interval between the termina¬ 
tion of the 25-foot curve in the channel and the outer crest of the bar ? 

The principles upon which a reply to these questions depends have 
been exhaustively treated in Chapter VIII of Humphreys and Abbot’s 
report on the physics and hydraulics of the Mississippi River; and 
there is nothing more to add, except the conclusions which follow from 
that report. 

Let us suppose, as the first effects of the jettees, the 25 foot curve to 
have advanced to the original outer crest of the bar. It will be found 
that the position of the crest has already advanced, due to the large 
amount excavated from the sides and bottom of the channel and the 
ordinary supply of materials which are rolled on the bottom and de¬ 
posited on the outer slope; and it is not certain that there would be a 
full depth of 25 feet at the new crest, on account of the tendency to 
form the upper surface of this deposit coinciding with the angle at 
which the [river-waters emerging from between the pier-heads would 
be deflected upward by the waters of the Gulf, an effect which the spread 
of the river-waters, after their release from the confinement of the jettees, 
would increase. The succeeding flood, while advancing the bar, should 
upon the same principles still further decrease the depth over its outer 
crest; and every advance of the bar would be followed by a similar re¬ 
sult. Thence the jettees, in order to retain the depth gained, should 
keep pace in their extension with the progress of the bar. At high 
water of river the deposits are made exteriorly ; at low water, interiorly. 
During the changes from high to low water, the deposits are made be¬ 
tween these two, or on what is ordinarily considered the bar. 

A condition of things likely to occur periodically, whereby a medium 
stage of the river, without high floods, might be maintained, would 
cause unusual deposits upon the bar; and hence an additional reason 
for the conclusion, apparent already from the first portion of this dis¬ 
cussion upon the bar, that in order to secure, at all times, a depth of 
25 feet, provision should be made in the arrangement of the jettees to 
excavate to a depth greater than that. (Note 0.) 

As a case in point, Major Stokes, royal engineers, in his paper upon 
the improvement of the Suliua mouth of the Danube, states, in 1863, 
owing to the absence of floods in the river, a bank formed within the 
pier-heads almost in the position of the old bar, greatly contracting 
the channel, though not actually barring it. 

If it is not already apparent that the deep space ahead will not of 
itself prevent the restoration of a shoal depth to the bar after once 
deepening it, reference may be had to the fact that a shoal bar, for over 
one hundred years, has been advancing at Pass a Loutre, over a deep 
space ahead, and at an average rate of about 300 feet a year. 

In proportion as the cross-section of discharge on the outer crest of the deposit 
widens, its progress into the Gulf will become slower, and the depth of water upon it 
will constantly decrease. ****** 

(Humphreys & Abbot, pp. 446, 447.) On the other hand, if the cross-section be nar¬ 
rowed, the progress into the Gulf of the deposits will become more rapid. 

This rapid extension of the pass into the Gulf would tend to increase the volumes 
of the shorter passes at the expense of its own, and it would eventually be necessary 
to resort to another pass for the continuance of the plan. (Ibid., p. 456.) 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 109 


This yearly progress of the bar demands a corresponding extension of 
the jettees into deep water opposed to the severe storms of the Gulf, 
and consequently of great cost. 

The difficulties at the mouth of the Mississippi, so far as concerns 
the improvement by jettees, resolve themselves into three sources: 

1. The absence of a littoral current. 

2 . The yielding nature of the banks and shoals. 

3. The abundance of deposits. 

The first and third combine in the yearly and rapid extension of the 
bar, and compel the works of improvement to continue at a heavy an¬ 
nual cost until their entire abandonment. 

The second makes their construction difficult and their maintenance 
improbable, unless deeply founded at a very heavy expense. 

All the principal objections to the improvement of Pass a Loutre 
necessarily apply to the Southwest Pass. 

But the board does not clearly understand why Pass a Loutre has 
been preferred for improvement by jettees, its exposure to the storms 
and storm-tides of the Gulf being much greater than that of the South¬ 
west Pass; and it may be added that the direction of jettees at the 
Southwest Pass would be straight, while at the other pass they would 
be inclined to the direction of the current, which is objectionable. 

Pass a Loutre, however, has the advantage of being directly in the 
track of vessels bound to and from the East. The lengths of both 
jettees at Southwest Pass, designed for the same objects as at Pass a 
Loutre, would amount to 54,000 linear feet. It is proper to state that 
these lengths were taken from a Coast Survey map, of a scale smaller 
than that of the map of Pass a Loutre, made by the engineer in charge 
for the operations of the dredging-machine, and upon which the improve¬ 
ment of Pass a Loutre was discussed by the board. 

In the study of improvements of this character it is well to refer to 
instances where trial has been made, holding ip view always the sound 
principles that the fact of work having proved successful, or having 
failed, at any river mouth, by no means insures that the fame kind of 
works will succeed or fail at any other river mouth unless the very same 
conditions exist. 

The board is indebted to the article (vol. XIII, professional papers) 
of Major Stokes, li. E., British commissioner for the improvement of 
the mouths of the Danube, for much of the matter in the present dis¬ 
cussion immediately following. 

From 1594 to 1082 attempts were made to improve the Vistula by ex¬ 
tending piers seaward from its mouth. U A breach in the root of this 
pier, through which the river cut itself a lateral communication with 
the gulf 10 or 12 feet deep, suggested the idea of obtaining a perma¬ 
nent channel independent of the mouth.” 

The extension of the piers from the mouth of this new channel con¬ 
verting it into a canal did not avail to secure the requisite draught. 
“The author was informed by the engineer who, in 1858, had charge of 
all the Prussian harbor-works, that no efforts were available to keep 
open a greater depth than 10 feet into the canal before the year 1840. 

* * * It was not till after the breaking through of another 

mouth several miles to the east, in 1840, as before mentioned, that the 
Prussian engineers could congratulate themselves on having obtained a 
good entrance to the port of Dautzic. * * * The river was 

at once shut off from its old course * ' * * by a dam. 

* * * The old mouth was cut off from the sea by a solid dam. 

* * * By these means an excellent channel of 17 feet was ob- 


110 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


tained,” (at the mouth of the canal,) “and has since been maintained 
by constant dredging. As already mentioned, the dredging is carried 
on under peculiarly favorable circumstances, as the Gulf of Dantzic is 
land-locked. * * * In the Gulf of Dantzic there can 

hardly be said to exist a littoral current. The littoral current of the 
Baltic, from west to east, passes along the Helas # # # 

and strikes again the coast, which then immediately trends to the north. 
The main force of the current is then carried northward, but a portion 
of it sets into the Gulf of Dantzic from east to west, * * * 

while a second current, passing round the head of the Helas, sweeps 
along the shore of the Gulf, and, traveling from west to east, meets the 
main current somewhere opposite the old mouth. No more unfavorable 
circumstances for the opening of the mouth of the river could be imag- 
iued. The river issuing into slack-water at the meeting of the two cur¬ 
rents threw down its deposits at once.” * * 

The two attempts, which were persevered in for more than one hun¬ 
dred and fifty years, to keep a channel open for sea-going vessels at the 
mouth of the river or of the canal, failed, and it was not until the fortu¬ 
itous opening of another mouth, live miles from the old mouth, which 
removed the deposits to a distance, that a success was obtained. 

The causes of non-success were : 

1. Absence of neutralization of littoral currents. 

2. Abundance of deposits. 

The causes of final success were: 

1. A stoppage of deposits. 

2. Dredging in a sheltered gulf. 

The character of the piers, which were chiefly built of riprap, as 
shown in the plates accompanying this article, indicates that the founda¬ 
tions were not of the yielding nature of the Mississippi deposits, and as 
there is no mention made of difficulties arising from the nature of the 
bed, it is assumed to havg been ordinarily good. 

The board passes to another instance of improvement, cited from the 
same author, of the mouths of rivers in tideless seas, viz, the Sulina 
mouth of the Danube. 

The improvement was made by the construction of parallel piers. 

The north pier is a continuation of the left hank of the river. It is 4,640 feet in 
length, and is carried out to what was the 16-foot line before the work was even begun. * 

The south pier approaches the north pier on a curve, and then runs 
parallel with it, terminating GOO feet short of the other pier. 

The construction was of an outer line of sheet-piling stayed by a 
framing of piles and timbers, the foot of the sheet-piling being pro¬ 
tected on both sides by a large deposit or bank of stone rising to the 
level of the water. At intervals there was an inner row of sheet-piling, 
with cross lines to the outer row, the space or box thus formed being 
filled with stone, and both rows protected on their exterior by a deposit 
of stone. 

Since the construction of piers the depth has never been less than 16 feet, and is 
usually 17 feet, there having been at times a good channel of ll\ feet. 

The piers were finished in 1861, and in 1863, the date of the article, the 
experience was that the depth varied at times from 16 to 17^ feet, the 
latter belonging to the floods of “unusual violence.” 

Spring floods of that year had formed a menacing bank on the continuation of the 
north pier, and about 2,500 ,feet to seaward of it, but this bank was speedily broken 
down oy the spring gales and carried away by the littoral currents. In 1862 the floods 
threw down a similar bank, but without obstructing the navigation, and that bank 
was again removed by the action of storms and currents. * * * The rapidity 

with w hich they were removed seems to favor the supposition that the bar will only 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. Ill 


creep across the front piers when the general advance of the delta should have pushed 
the littoral current further away from them, and thus have caused a double effect dan¬ 
gerous to the channel. 

In the first place, the river current would not then be turned southward, and would 
throw down its deposits immediately iu front of the piers ; * * * and, secondly, 

the banks thus formed, instead of being broken down by the gales and carried south¬ 
ward, would be driven back on the channel, which they would still more choke. 

Since this article was published, it is ascertained that the south pier 
lias been extended as far seaward as the north, and that a depth of 20 
feet has been obtained. 

The board are not in possession of a paper on the same subject, by 
Sir Charles Hartley, the distinguished engineer who constructed these 
piers, but it is impossible to entertain a question as to the causes of the 
success of the pier system at this place. 

An inspection of the map accompanying the article shows a great 
development of the delta form at the Kilia mouths, and the same for¬ 
mation to a less degree at the St. George mouth, with a consequent pro¬ 
jection outward of the shore line, but at the Sulina mouth no formation 
of the kind is distinctly traceable, and it is inferred, though the fact is 
not material, that the quantity of sediment emptied at this outlet is 
small in comparison with the others. 

The construction of the piers indicates a difference in the character 
of the bed, as to resistance, from that of the Mississippi, it being cer¬ 
tain that this description of work would not answer at the latter place. 

The cases of the Vistula and the Sulina mouth of the Danube mani¬ 
fest essential points of divergence from the circumstances attending 
the improvement of the Mississippi, and the results obtained in the 
former-cases constitute no precedent for the employment of the same 
means at the latter place. 

Upon a review of the practical difficulties which the adoption of the 
jettee system of improvement at the mouth of the Mississippi would 
entail, and a due consideration of the original cost of construction and 
of annual extension, entertaining doubts, moreover, of the successful 
issue of the attempt, the board do not consider it advisable to recom¬ 
mend it. 

With regard to the cost of this operation, owing to the uncertain na¬ 
ture of the problem, made so by the peculiar risks attending it, the 
board find it impossible to fix any reliable limits. 

The estimate in this report, made upon a hypothesis favorable to the 
project, indeed, but which does not exist, is useful only to convey to 
the mind some idea of the magnitude of the undertaking. 

As an auxiliary to the improvement by jettees of the mouths, dredge- 
boats must be employed to remove mud-lumps. 

The other means of improving the depth at the mouths, by the stir- 
ring-up process, has already been put to the test of practice. 

Two boats, the Essayons and the McAlester, have operated upon 
Southwest Pass and upon Pass a Loutre. 

These dredges can begin work upon a bar having only 11 feet of water. 
The former can excavate to a depth of 20 feet, the latter boat to a depth 
of 22 feet. 

Operations at Southwest Pass between July 1,1872, and April 1,1873 : 
The width of the channel made, varied from 50 to 150 feet. The depth 
varied from 20 to 13 feet. For 30^ days, 19 to 20 feet in depth; for 120 
days, 17£ to 19 feet in depth; for 90 days, 17 feet in depth 5 for 22 
days, 13 to 16 h feet in depth. 

The smaller depths, from 13 to and including 17 feet, were due mainly 
to blockades and other obstructions formed by grounding vessels. 

From July 1,1872, to April 1,1873, 53 vessels grounded at Southwest 

( 


112 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Pass, and were the cause of there being less than IS feet in the 
channel after November 1. To April 1, 1873, the dredges worked 58 
days. Suspension of work on account of slack current, 62 days; fogs, 
21 days; waves, 16 days; repairing, 36 days. The remainder of the 
time is accounted for in coaling, pulling grounded vessels out of the 
way, and suspension of work on Sundays. 

Operations at Pass a Loutre from April 1 to June 30, 1873: Starting 
at 11£ feet depth on the bar, worked 78 days. From May 27 to July 
1, the depth was 17£ feet at extreme low water of the Gulf. 

This favorable comparison of working-days at Pass a Loutre is due 
to several causes, viz, the small number of vessels passing through; 
the absence of grounding; the protection which the outer shoals afford 
to the bar, and the sufficiency of the currents during the period in ques¬ 
tion. 

It should be noted that the stoppages were from causes beyond con¬ 
trol, and, consequently, which could not be remedied by better boats or 
more of them. The grounding of boats, the stoppages, and the shoal¬ 
ing in consequence thereof, could, however, have been prevented in 
many cases by good regulations, well enforced. 

The effect of the stirring-up process is to sift out the finer, leaving on 
the bottom the heavier, sandy particles, thus forming a surface harder 
than the natural one of the bar. Nevertheless, vessels pulled with pow¬ 
erful tugs are drawn through with a draught greater by one foot than 
the depth of channel. This operation would not generally succeed with 
long sea-going steamers. 

The results so far do not warrant the board in estimating a greater 
depth than 18 feet at extreme low water as capable of being maintained 
at the passes by means ot the stirring process. This is inadequate to 
the requirements of naval, military, and commercial services. 

Although the stirring-up process cannot, therefore, be made a substi¬ 
tute for a project affording the proper depth, it should be continued 
until such project shall have been completed. 

It is understood that one member of the board of 1852, Major Chase, 
(now deceased,) was in favor of the canal project, (Note D.) Another mem¬ 
ber, Major Beauregard, has expressed his opinion very emphatically in fa¬ 
vor of a ship-canal, and doubtfully as to the jettee system. This testimony 
is valuable, as springing from the matured judgment of an experienced 
engineer, well acquainted with the subject he discusses, and is an evi¬ 
dence of a prevailing conviction which points to the fact that the time 
has come for obtaining an outlet to the ocean of depth sufficient to 
meet the necessities of the great valley of the Mississippi, and that the 
canal offers the best and most certain means of attaining this result. 

JOHN NEWTON, 

Lieutenant-Colonel of Engineers , Brevet Major General. 

Q. A. GILLMORE, 

Major of Engineers , Brevet Major-General. 

WM. P. CRAIGHILL, 

Major of Engineers. 

G. 'WEITZEL, 

Major of Engineers , Brevet Major- General. 

C. W. HOWELL, 

Captain 'of Engineers , Brevet Major. 


Not fully concurring in the above, my views will be submitted in a 
separate report, 


J. G. BARNARD, 

Colonel of Engineers and Brevet Major-General. 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 113 


Dissenting from the report of the board in but one point of opinion, 
I have signed the report, reserving mention. Referring to my report 
on the canal, also to my answer to a letter addressed me by the president 
of the board, both submitted with the report of the board, it will be ob¬ 
served, as the probable depth of channel to be maintained by dredging 
on the bars under stated conditions, I name 20 feet. This is considered 
by the board an over-sanguine estimate, more especially since the past 
record of dredging does not show the maintenance of an 18-foot channel. 

While adhering to my opinion, I must acknowledge, so far as 1 know, 
I am the only engineer holding it. 

C. W. HOWELL, 
Captain of Engineers , U. S. A. 

Note A.—The operation of closing the north mouth by a work which 
at the same time changes the direction of the current, appears to be 
doubtful of success, as well as excessive in cost; and the question arises 
whether it would not be better, first, to close the mouth by a dam bfelow 
the position of the works, and then to construct the line of jettee. In 
this way the difficulties would be separately met, and the cost might be 
kept within limits capable of being fixed. 

Note B.—The influence of the jettees will develop additional forces 
tending to change the form and equilibrium of the shoals. 

Note C.—And hence the jettees, in order to carry into the Gulf a depth 
greater than 25 feet, must be of greater length, at a less distance apart, 
founded in deeper water, and situated farther down the slope of the 
banks, all of which circumstances are unfavorable, as to the cost and 
difficulties of construction. 

Note 1). —Major Chase had, in 1837, submitted a project and esti¬ 
mate for a ship-canal. 


Army Building, 

New York, January 29, 1871. 

General : In a partial report, January 20, confined to the discussion 
of the u plan submitted by Capt. C. W. Howell, Corps of Engineers, for 
a ship-canal to connect the Mississippi River with the Gulf of Mexico,’ 7 
I stated that in another report “ I shall maintain that before resorting 
to an artificial work of the difficult and costly character of a ship-canal, 
a more attentive consideration of the superior advantages of the natural 
mouths, and of the fair probability of utilizing them, is needed. 77 

This investigation is called for by your expressed desire “to have the 
views of the board of engineers on the question as to the expediency of 
improving the navigable waters of the Mississippi by the Fort SaintPhilip 
Canal as an alternative to or a simultaneous measure, perhaps, with the 
improvement of the passes, 77 and as I could not concur in the views of 
the majority of the board on these subjects, this separate exposition of 
my own is rendered necessary. 

There are but two methods of improving the passes which call for 

notice: . . . . 

1st. Dredging , in which may be included all the varieties of that pro¬ 
cess, such as “ stirring up, 77 “ harrowing, 77 &c. 

2d. Jettees at one or more of the mouths by which to concentrate the 
current upon the bar and thereby cause its removal. 

II. Ex. 220-S 



114 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Of the first process only has any actual knowledge by experiment 
been attained, and some notice of the history of this experience will be 
iu place. 

Under the first appropriation for the improvement of the mouths of 
the Mississippi, in 1837, “dredging” with “buckets” was recommended 
by a board of engineers, and a powerful machine constructed and set to 
work. But its cost and the outlay upon the survey consumed the ap¬ 
propriation before the method had been tested ; and no other appro¬ 
priation was made till 1852. In that year an appropriation of $75,000 
was made for opening “ a ship-channel of sufficient capacity to accom¬ 
modate the wants of commerce;” and it was further provided that the 
said money should be applied by “ contract,” and that the contract 
should be “ limited to the amount appropriated.” 

Iu order to decide how to apply this appropriation under the stipula¬ 
tions of the law, the Secretary of War (Mr. Conrad) convened a mixed 
naval and engineer board, (its members were fhe late Commodore W. 
K. Latimer, U. S. N., the late Maj. W. H. Chase, United States En¬ 
gineers, Maj. G. T. Beauregard, United States Engineers, and the under¬ 
signed,.) and submitted to it certain queries. All these officers had 
served long on the Gulf coast, the three latter, as engineers, having 
had much experience with construction and engineering problems con¬ 
nected with the Lower Mississippi. Major Chase had, indeed, been one 
of the very first engineers to propose, in 1837, a ship-canal, and the 
first to define his views by a project, which has been noticed in my first 
report. 

No other plan suggested itself to that board by which the $75,000 
could be applied with some hope of obtaining any important result than 
that of “ stirring up ” the bottom ; and upon their recommendation a 
contract was entered into with the Tow-boat Association, by which a 
chanuel through the bar at Southwest Pass 18 feet deep and 300 feet 
wide was to be made. The execution of this contract was the very 
first successful application of any artificial means to deepening the 
channels over the bars, and it demonstrated the efficiency of dredging 
by that method. Inasmuch, however, as the board could not foresee 
with certainty this success, they, in recommending another appropria¬ 
tion of $150,000, also recommended, should in the meantime the dredging 
processes prove failures, to apply it to the construction of jettees of the 
Southwest Pass, remarking that the “ project of jettees is based upon 
the simple fact that, by confining the waters which now escape use¬ 
lessly in lateral directions to a narrow channel, the depth of this narrow 
channel must be increased—in other words, the existing bar must be 
cut away.” As auxiliary to the jettee system, the board recommended 
the closing of certain minor outlets in order to increase the volume 
flowing through Tass a Loutre. The board concludes by saying that, 
should methods of operating upon the natural outlets—the mouths— 
“all fail,” there is yet a plan to fall back upon, viz, A ship-canal. 
They express their conviction of its practicability, and recommend “that 
the engineer charged with these works should be directed to employ 
such time as he can spare to an investigation of the subject, having- 
reference to the possibility of a future recurrence to this project.” 

No further appropriation was made till 1850, and as a consequence 
the 18-foot channel completed in 1853 was speedily filled. In the year 
mentioned an appropriation of $330,000 was made for the improvement 
of the passes. A board of engineers recommended that the proposals 
of the Tow-boat Association should be accepted for keeping open the 
Southwest Pass, by the already successfully tested method of stirring 


i 


IMPROVEMENT OE MOUTH OF THE MISSISSIPPI RIVER. 115 

up the mud, and that a proposal of Messrs. Craig and Righter for 
keeping open Pass a Loutre by means of jettees, and closure of minor 
passes, be accepted. 

By direction of the Secretary of War (Mr. Davis) their plans and pro¬ 
posals for both passes were accepted, and the contractors began at the 
Southwest Pass, by building on the east side a jettee about a mile long, 
composed of a single row of pile pi antes, strengthened at intervals by piles. 
Portions of this jettee were carried away by storms, and the contractors 
abandoned the plan, and were permitted to resort to the “stirring-up 77 
method, by which they opened, in 185cS, two channels 18 feet deep, 
which, as long as the process was continued, preserved this depth. 
(Physics and Hydraulics of the Mississippi, p. 455.) 

Such, substantially, was the experience up to the interruption of all 
operations by the civil war. 

In 18G7 an appropriation of $75,000 was made, and a contract en¬ 
tered into, for “ stirring up,” which, however, was not executed. 

The engineer in charge (the late Maj. M. D. McAlester) then designed 
a boat (the Essayons) especially adapted to the stirring-up process, by 
agency of propeller-blades extending below the keel, and, with the bal¬ 
ance of the appropriation just named and that of 1867, ($200,000,) the 
vessel was built, and the system, as improved by Major Howell, by the 
addition of the deflector, which more effectually directs the stirred-up 
material into the upper currents, has been since in operation, with emi¬ 
nent success. 

“The results have been such” (in the language of Major Howell) “as 
to warrant yet more liberal action. With the success attending the 
work of dredging the bar at Southwest Pass during the past two years, 
the commerce seeking the port of New Orleans has grown rapidly. 

“Lines of steamships before in the trade have built new vessels for it; 
other old lines have been attracted to it; newlines have their vessels 
in course of construction, and sailing-vessels in greater number than 
before have been engaged in it, all taking fuller cargoes, making quicker 
trips, with greater profit to owners and reduced expense to shippers. 
The cotton trade of the upper cotton region, for a time partially diverted 
from this route, is returning, and a grain trade has been inaugurated 
which promises to attain large proportions. 

“While the great benefit already derived from dredging is acknowl¬ 
edged, there remains in the minds of commercial men doubt as to its 
continuance to meet the growing demand for deeper-draught vessels. 

“ There is yet more serious doubt regarding the continuance of suit¬ 
able action on the part of Congress, in making appropriations seasona¬ 
bly and in amount to prevent interruption of the work. Distrust in the 
continued effectiveness of dredging can only be overcome by long-con¬ 
tinued success, and simply retards commercial progress. 

“ Distrust of the continued good will of Congress is of more serious 
import. The work in progress is dependent for its continuance on an 
annual appropriation. It is of a character requiring continued work. 
Suspension for a few weeks or months will permit the natural agencies, 
always at work, to obliterate all evidences of previous improvement, 
and return the channels across the bar at the river-outlets to their 
normal and obstructed condition. 

“ Such occurrence would be disastrous in the extreme. It would 
ruin the commerce now promising such good results, ruin the merchants 
now engaged in it, and destroy confidence in plans for its revival at any 
future time. Yet such occurrence is not improbable, as evidenced by 
the past record of the work. 


116 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


“Legislative economy enters too largely into the spirit of American 
politics to permit of men engaged in legitimate business staking their 
wealth, when it will depend on the turn legislation may take. What 
is required to inspire confidence in the future of the commerce of the 
Mississippi River is a permanent outlet—not one of uncertain tenure. 
Dredging, from its dependence on legislation, does not offer such.” 

It is further stated by the engineer in charge, in an official letter to 
the president of the board, that, provided that enough money be fur¬ 
nished to keep the two dredge-boats now in service employed all the 
year round, except when under repair, and further provided the engi¬ 
neer have full control over the use of the channel, with authority to 
assess fines in cases where injury may result from ignorant or malicious 
handling of vessels in the channel, to be collected in the United States 
courts, then a channel may be made and maintained at one of the 
passes with 20 feet depth at extreme low tide ; and the cost for the same 
would be $150,000 per annum for “running expenses,” and a new 
dredge-boat, costing $250,000 every five years, or an average cost of 
$200,000 per annum. (See letter of Major Howell, appended.) 

If these official expressions of the engineer in charge be not deemed 
strong enough, reference may be made to the following passages from 
his annual report of September 18, 1873 : 

That natural causes effecting a "blockade of the mouth of the Mississippi have been 
overcome by the system of dredging adopted, so far as regards obtaining a 20-foot chan¬ 
nel across the bar at the Southwest Pass, is evidenced by my reports. 

Even the popular prejudice against dredging has been overcome, and the people of 

New Orleans, most interested to-day, acknowledge the good done. 

# * * #/ * *■ #• * 

In consequence, with means at my command abundantly able to overcome all natural 
obstacles to the formation and maintenance of a good channel at the mouth of the Mississippi 
River , I have not been able to accomplish the latter, and this fact, with those who do 
not appreciate the other facts, discredits my work, the system of dredging, and my 
ability as an engineer, &c. 

It has already been stated that the very first attempt at “ stirring up 
the bottom” successfully created a channel on the southwest bar 300 
feet wide and 18 feet deep, for the sum of $75,000. Subsequently, 
(1858,) Messrs. Craig & Righter having failed in their efforts at jettee 
construction, succeeded, by means of “ stirring up the bottom with har¬ 
rows and scrapers, dredging with buckets in some places,” &c., in 
making two channels 18 feet deep, and as long as the process of stirring 
up the bottom was continued by them , the channels preserved the requisite 
depth” (Phys. and Hyds. of tlieMiss., p. 455.) Subsequently (1839) the 
Department took the work in hand, still using the plan of stirring up 
the bottom by “dragging harrows and scrapers” over it. “The plan 
proved to be successful, and a depth of 18 feet was mantained upon the 
bar for the period of one year, at a cost of $60,000.” 

Thus we see that the very earliest attempt, by improvised methods, at 
scratching the surface of the bar with harrows, &c., produced, for $75,000, 
an 18-foot channel 5 that the process was repeated in 1858 with the 
same success, and two 18-foot channels obtained; and finally, the thing 
was again done under the immediate direction of the Department, and 
for the small sum of $60,000 a depth of 18 feet was maintained for a 
period of one year. 

In face of these facts ; in face of the positi ve, formal, and official 
statement of the engineer in charge “ that, so far as regards obtaining a 
20-foot channel , the natural obstacles have been overcome, (reiterated 
under different forms,) and in face of the fact that since the proved 
success of stirring up by scraping with harrows, &c., for $60,000 a year , 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 117 


machinery expressly designed to this end has been invented and im¬ 
proved upon, under the eye of engineer officers, to be operated at an ex 
pense of two hundred thousand dollars per annum, the majority* of the 
board advise you that u the results, so far, do not warrant the board at 
estimating a greater depth than IS feet, at extreme low water, as capa¬ 
ble of being mantained at the passes by means of the stirring-up pro¬ 
cess 5 1 and, furthermore, that u this is inadequate to the requirements of 
the naval, military, and commercial services.” 

By reference to the best authority I have proved the adequacy of 
dredging operations on the bar by well-tested means ; but I think there 
is yet room for improvement, and especially in diminishing cost. The 
utilization of the power of the current may perhaps be yet further 
effected,! while the attainment of 20 feet depth on the bar has by no 
means been established to be the maximum. As to that depth, however, 
we have the strongest assurances. 

With 20 feet at extreme low tide, vessels drawing 22^f feet could, owing 
to the softness of the bar, frequent the port of New Orlens, and for mere 
commercial purposes probably 20 feet draught would be adequate. A 
draught of 23 feet will include 85 per cent, of the shipping of the world ; 
and with a draught of but 18 feet vessels (steamers) can be built of 5,000 
tons, carrying 70,000 bushels corn, or about 11,000 bales of cotton.§ It 
is clear, then, that, for commercial purposes, a depth of 20 feet on the bars 
of the passes will suffice to furnish a navigable outlet, and relieve the 
commerce of the valley from enhanced charges, arising from insufficient 
tonnage in the transports. 

The engineer has, in language already quoted, very forcibly described 
the impetus given to commerce through the passes by the successful 
dredging operations of the last two or three years ; but the benefit, he 
says, is qualified partly by the doubt whether the process will meet the 
u future demands for vessels of deeper draught,” but still more by doubt 
as to the uninterrupted annual appropriations by Congress ; and hence the 
real obstacle to that confidence which will justify business men in invest¬ 
ing their money in lines of steamships of magnitude such as will bring 
the cereals and cotton of the valley through this route, appears to be 
uncertainty as to the annual appropriations by Congress. 

The remedy for this is clearly pointed out in the “ Physics and 
Hydraulics of the Mississippi,” in the very last paragraph of that work, 
(p. 156,) viz, u that a permanent fund be provided, untrammeled by 
restriction as to the mode of the expenditure, from which a sufficient 
sum annually can be relied upon for the continuous prosecution of the 
work,” &c. 

* The engineer, Captain Howell, of course, could not concur in our opinion iu so direct 
conflict with his official statements. In his paragraph of dissent he avows himself to be 
4( the onlv engineer, so far as he knows.” who believes his own assertion that the “ natural 
obstacles to obtaining a 20-foot channel across the bar of the Southwest Pass have been 
overcome ,” or who is so “ sanguine” as to believe that with the two powerful and espe¬ 
cially designed dredge-boats, and $150,000 per annum, he can accomplish more than 
has been accomplished bp others without such machinery, and for $60,000. But he cer¬ 
tainly knew m\j opinion ; not a singular one, I imagine, or one for which it would be of 
importance to cite names. 

t A simple design was made by one of the members of the board of 1852, (Major 
Beauregard,) and again brought to the attention of the general board. Its trial was 
urgently recommended by all the members of the first-named board, and by other com¬ 
petent judges. 

+ Average high tide is about 11 feet above “ extreme” low tide. Vessels drawing a 
foot more than depth on bar can (though with some difficulty) pass. On the miter- 
sills of a lock a clearance of 1 foot is stated to me by one of our naval constructors to 
be necessary for vessels of heavy tonnage and large draught. 

^ See prospectus of Atlantic, Great Western, and Southern Steamship Company. The 
proposed vessels draw but 18 feet. 



118 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

Congress lias power, I presume, to provide such fund, or to make ap¬ 
propriations applicable for future years. But if absolute f reedom of use 
be not claimed for the canal, if tolls enough merely for maintenance be 
imposed, then with equal propriety an amount no greater (for no greater 
is needed) may be raised from vessels passing the deepened bars. 

An objection to a reliance upon the dredging process is urged that it 
could not be maintained during a period of war with a powerful mari¬ 
time enemy. This objection implies a state of continuous blockade at the 
mouth of the river, and a protracted war. Protracted wars between 
powerful nations are no longer probable$ they are ceasing to be possible ; 
while the supposition of continuous blockade to one of our greatest sea¬ 
ports woidd be repelled, and indeed would be more destructive of the 
commercial use of the river-mouths than the usual bar obstruction. 

The objection is not therefore in the same category with the demand 
for the defense of the works of an artificial canal, and it is not an over¬ 
ruling one. Still an improvement of one or more of the natural mouths 
by which a sufficient depth should be afforded without the continuous 
use of machinery, and which would not be subject to the objection just 
cited, would be desirable. 

In turning to the subject of jettees, I do not know how I can better 
define at the outset my position in relation to them than by quoting 
from the draught of a report which has been submitted to the board, 
and which has already passed through your hands : 

I can only reason on jyrobabililies deduced from study of the river and the lights of 
experience ; and so long as to establish the negative there has been, I need not say, no 
trial of the system, but not even a survey accompanied with a careful study and experi¬ 
ments, directed expressly to develop the cost and character of the work needed, I feel 
that I am justified in recommending it as probably furnishing the most speedy attain¬ 
ment of a deep-water channel, and one which wili have some features of permanence 

Iu a passage’already quoted from the report of the board of 1852, the 
rationale of the jettee system is explained. I further cite from the 
u Physics and Hydraulics of the Mississippi ” the following : 

The development of the laws which govern the formation of the bars has removed all 
uncertainty as to the principles which should guide an attempt to deepen the channel over 
them. The erosive or excavating power of the current must be increased relati vely to the 
depositing action. This may be done either by increasing the absolute velocity of the cur¬ 
rent over the bar or by artificially aiding its action. To the first class of works belong 
jettees and the closure of lateral outlets ; to the latter stirring up the bottom by suit¬ 
able machinery, blasting,, dragging the material seaward, and dredging by buckets. 
These plans are all correct iu theory, and the selection from them should be governed 
by economical considerations. 

Sucli is the theory, and no engineer has yet expressed a doubt as to the 
fact that concentration of the waters of one of the passes by jettees 
carried out to deep water, woidd excavate the required deep channel. 
The difficulty and the cost of construction, the alleged necessity of 
costly annual extension, furnish the arguments why this method should 
not be resorted to. While the general laws which govern the formation 
of bars at river mouths are universal, there are peculiarities in the 
formation due to the natural differences of character of the rivers and 
of the sea-shore where the mouth is situated. If the shore be itself 
sand or gravel, and not rock, a bar always forms, whether the river 
brings down sediment or not. The latter material cannot, therefore, be 
regarded as in any sense the cause of the bar, though when it exists it 
is found to be the material of which the bar is composed. The most 
intractable bars are usually found to be of the former class $ and yet, 
with few exceptions, every harbor on our northern lakes constituted by 
a river or creek mouth has been improved by the construction of par- 



IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 119 


allel jettees. That those jettees need sometimes to be prolonged is no 
denial of their efficacy. 

In the thirteenth volume of the professional papers of the Royal 
Engineers, lour different instances of the application of jettees are de¬ 
scribed: two, the Danube and the Oder, (the first a sediment,the second 
a non-sediment-bearing river,) successfully 5 another, the Vistula, (sedi¬ 
ment-bearing,) unsuccessfully; and the fourth, the Rhone, of which it is 
stated : u They cannot be said to have failed, (for they were never fairly 
tried,) though their failure there would constitute 110 argument against 
their employment elsewhere.” 

Concerning the ^ istula it is stated, u no more unfavorable circumstances 
for the opening of the river could he imagined ” than those that existed at 
the old mouth, where, for 150 years, jettees (always used , however) failed 
to produce an adequate permanent depth. In 1840 the river burst through 
a narrow tongue ot land and formed a new mouth, live miles from the 
old one, to which “piers” (jettees) were immediately applied, by the effect 
ot which, aided by dredging, a depth of 17 feet is obtained. Jettees 
were not, therefore, total failures, after all. 

At the mouth ol the Adour, below Bayonne, (not cited in the volume 
referred to,) piers were carried out one and a half miles long in nearly 
parallel lines and with a narrow channel. The bar here was u shingle,” 
(?*. e., gravel or pebbles,) and the operation is described (Minutes Insti¬ 
tution Civil Engineers, 1861-’62) as “ a total failure.”* 

The conspicuous instance of the success of jettees is that of the Danube 
mouth. Here, as in the case of our own great river, a great sediment¬ 
bearing t river discharges into a (nearly) tideless sea: 

I he base of the triangle which constitutes the delta forms upon the general outline 
of the coasts of the Black Sea a strongly-pronounced salient, which is connected with 
the primitive shore-line by curved contours. A complete analogy is thus found between 
the form ot this delta and those of the great rivers, the Nile, Ganges, and Mississippi. 
(Annales des Ponies et Chassees, Nov., 1872.) 


Nevertheless, compared with the Mississippi delta, there are very 
strongly-marked differences: 

There were at the Danube delta two natural actions going on. Opposite to each of 
the mouths of the river there was an accumulation; between the mouths there was an 
erosion of the shore. If the river had not been there it was natural to suppose that the 
whole of the shore would have been eaten away uniformly ; and therefore the amount 
of solid matter brought down by the river was not to be measured by the apparent 
width of the extension opposite to the mouths, but by the width of that extension 
added to the width of the recession in the parts between the mouths. This tendency 
to erosion from causes independent of the river was another circumstance conducive to 
success. (Minutes of Proceedings of Institution of Civil Engineers, vol. xxxvi, p. 231.) 

And, again, the formation (at the Sulina month, at least) exhibits 
firmness and (sometimes) even hardness. The village of Sulina, at the 
very month, is, in part at least, of stone buildings, on the natural soil. 
The bar sometimes, and especially during times of Hoods of the upland 
rivers, (the first effect of high floods having been with the improved 
bar to deepen it, the second to reform it further out, and of harder ma¬ 
terials,!) being incr'usted with hard sand, which yields with difficulty to 
the plowing action of a vessel’s keel, and the lateral shoals on which 
the jettees were laid being sufficiently firm to support u riprap” con¬ 
struction without materially yielding. 


* Nevertheless the depth is said to have been increased ; but inside, at a distauce of 
half a mile fiom the original bar, an interior bar was formed, due probably to the sea- 
waves’ action on the shingle. 

tThe ratio of solid to fluid in the Danube waters is by volume t Af j nearly the same 
as for the Mississippi. 

t The usual depth was about 9 feet, varying, however, from 74 to Ilf feet. 



120 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


Another point of alleged difference, very much insisted upon by many, 
is the littoral current off the Danube mouths. Colonel Stokes, K. E., 
(British commissioner,) states: 

Its existence was ascertained before the works were carried out, the author having 
instituted a series of observations with floats to test the amount of the current, the 
result of which proved that there was a decided current across the mouth of the river, 
which extended as low as 4 feet below the surface in a depth of 10 feet. The depth cn 
the bar at that time was 8 or 9 feet. It was also shown that during calms, northerly 
and northwesterly winds, there was a considerable littoral current from north to south, 
and during southerly and southwesterly winds, a surface current from south to north ; 
but it was so feeble as to indicate that the force of the wind had but just overcome 
that of the current from north to south. In strong westerly winds there was a counter- 
current setting in about 5 feet or 6 feet below the surface ; but this was not observed 
during the northerly winds, which so generally prevailed at the mouth. The Kilia 
branch, fifteen miles north of the Sulina, discharged two-thirds of the water of the 
Danube into the Black Sea, the whole of which set past the mouth of the Sulina. 

Seamen found a very constant current of from one-half knot to one knot per hour, 
setting from the north to the south along the coast of the delta. Colonel Stokes there¬ 
fore thought it established that there was a littoral current generally from north to 
south across the Sulina mouth. (Minutes of Proceedings of Institution of Civil 
Engineers, vol. xxxvi, p. 247.) 

To the undersigned Sir Charles Hartley stated that the current aver¬ 
aged about half a mile, confirming also the fact of its occasional fluctu¬ 
ation . 

Again it is to be observed that while each particular pass (and even 
each small u bayou”) of the Mississippi delta thrusts out, in its own par¬ 
ticular finger-like promontory, the Sulina mouth is not thus thrust out, 
but is on the general line of the shore. 

The Danube divides at about fifty miles from the coast into the Kilia 
and Toulcha branches, of which the former conveys two-thirds (about) 
of the entire discharge. The latter and more southern branch again 
divides into the Saint George and Sulina arms; the latter running 
eastward nearly. The Saint George conveys nearly one-third, leaving 
to the Sulina but two twenty-sevenths. The mouth of the Kilia and 
St. George are about 40 miles separated, the Sulina mouth nearly mid¬ 
way between them, the trend of the coast line being north and "south. 
Finally it may be said, the discharges of the Saint George and the South¬ 
west Pass of the Mississippi have the same ratios, one-third of the total 
discharge, and the Sulina the same ratio as the South Pass, (7^ to 8 per 
cent.) Hence, the total discharge of the Mississippi being more than 
three times that of the Danube, the Southwest Pass discharges three 
times as much as the Saint George, and the South Pass three times as 
much as the Sulina. The current velocities are, if anything, somewhat 
greater in the Danube than in the Mississippi, the inclination of surface 
in the Sulina 3 inches per mile during floods, and about one inch per 
mile at low water. 

The sea-depths at three miles from land are 16 fathoms off the Saint 
George, and only 10 fathoms off the Kilia and Sulina. 

On the other hand, at 1,000 feet outside the bar of the Southwest Pass, 
the Gulf is about 22 feet deep; at 4,700 feet, 100 feet deep; at 43,000 
feet (8 miles) 300 feet deep; and eleven miles, 900 feet deep, 150 fathoms. 
(Physics and Hydraulics of the Mississippi, p. 444.) 

The Kilia, though the greater arm, was deemed ineligible in conse¬ 
quence of its subdivision into numerous small delta arms of its own. 
To the Saint George, possessing a good navigable channel with 16 feet 
of water, (while that of the Sulina, with but 13 feet, was very bad,) was 
given the preference. 

When the engineer presented his plans to the European commission 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 121 


it liad three other designs before it “from eminent technical authorities 77 
who had visited the ground: 

In one respect alone all were agreed, and that was in recommending that whichever 
mouth were chosen, the system of improvement should be that of guiding the river- 
waters across the bar, by means of piers projected from the most advanced dry angles 
of the mouth; or, in other words, that of concentrating the strength of the river-cur¬ 
rent, on the bottom of the proposed improved seaward channel, by an artificial prolon¬ 
gation ot the river-banks into deep water. (Minutes of Proceedings of Institution of 
Civil Engineers, vol. xxi, p. 284.) 

The English, French, Prussian, and Sardinian governments then re¬ 
ferred the whole subject to the decision of two military and two civil 
engineers. These gentlemen, in an elaborate report, unanimously con¬ 
demned the jettee system, and “recommended the choice of the Saint 
George branch with a sea-entry and gates/ 7 (in other words, a “ship- 
canal, 7 ’) “independent of the mouth; a project diametrically opposed in 
principle to the system of improvement previously proposed by all the 
naval and engineering authorities, who had visited the several mouths of 
the Danube, and had studied their peculiarities on the spot. 77 (Ibid.) 

The final result of these complications, and of the impatience of the 
merchants for some immediate relief, was that the commission, under 
advice of its engineer, “resolved to improve the channel across the bar 
of the Sulina branch, by means of guiding piers of a temporary charac¬ 
ter, but carried out in the lines which the author had designed for per¬ 
manent works. 77 

It is not in place to go into particulars concerning the progress of a 
work protracted through many years through inadequacy of funds. 
The piers, as designed, were 5,850 and 4,310 feet long, starting at points 
on shore 2,500 feet apart, and converging to parallelism about 600 feet 
apart. 

The results are thus stated by Sir Charles Hartley, (Minutes of Pro¬ 
ceedings of Institution of Civil Engineers, vol. xxxvi, pp. 208, 209:) 

1. That when the European commission of the Danube began its labors, in 1856, the 
entrance to the Sulina branch was a wild, open sea-board stream, with wrecks, the hulls 
and masts of which, sticking out of the submerged sand-banks, gave to mariners the 
only guide where the deepest channel was to be found. 

2. That the depth of the channel varied from 7 feet to 11 feet, and was rarely more 
than 0 feet. 

5. That the site now occupied by wide quays, raised high above flood-level and more 
than two miles in length, was then entirely covered with water when the sea rose a few 
inches above the ordinary level, and that, even in a perfect calm, the banks of the river 
near the mouth were only indicated by clusters of wretched hovels built on piles, and 
by narrow patches of sand skirted by tall weeds, the only vegetable product of the vast 
swamps beyond. 

4. That in the summer of 1857, three months of constant dredging and raking on the 
bar produced no appreciable effect. 

5. That on the completion of the provisional piers, in 1861, the depth on the bar in¬ 
creased to 17 feet, and Sulina, instead of being the worst harbor, at once took the highest 
rank among the best commercial harbors in the Black Sea. 

Finally, by the prolongation of the south pier, the consolidation and 
rendering permanent the work, at an expense equal to the first cost of 
the temporary structure, and by other improvements, an effective depth 
of 20 feet was attained in 1872, and since maintained.* * 

So far from a rapid advance or protrusion of the bar having ensued, 
“the piers have hitherto had the effect of diminishing by more than 
one-half the old rate of the advance of the delta at the Sulina mouth 
as represented by the 24-foot line and 30-foot line of soundings; of en- 

* Since the prolongation of the south pier had prevented the formation of the bank 
between the two pier-heads, there had been no symptoms of deterioration of the channel. 

* * * * Vessels had passed out during the spring of the current year drawing 

20 feet 3 inches.—(Discussion of a paper by Sir Charles Hartley, May 13,1873, Minutes of 
Proceedings Institution C. E., vol. xxxvi.) 




122 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 

couraging the growth of the sand banks directly under the shelter of 
the south pier; and of causing a rapid erosion of the sea-bottom north¬ 
ward of the north pier along its whole length, an action which has 
naturally extended itself to the line of shore, thus necessitating, as has 
already been observed, a prolongation of 094 feet from the shore-end of 
the pier. The causes of these phenomena may be briefly explained as 
follows: The slower advance of the delta, as limited by the tails of 
the 24-foot bank and of the 30-foot bank, is due to the circumstance 
that the great bulk of the silt-bearing waters of the river, on issuing, 
as at present, at once into deep water beyond the pier-heads, is, as a 
rule, carried far to the southeast by the littoral current, instead of 
flowing into the sea, as formerly, with a feeble and constantly decreas¬ 
ing current, by numerous shallow channels, which were always changing 
in direction and extent. * * * * The remarkable ero¬ 

sion to the north of the piers is probably chiefly due to the rebound of 
the sea against the north pier during heavy northerly and northeasterly 
gales.’’ 

Simultaneously with this it is observed that opposite the Ochakoff 
mouth of the Kilia, the 6-foot line of soundings has advanced 6,000, 
and the 30-foot line 5,000 feet, since 1856, or at the rate of 333 feet per 
annum.” 

I have thus given, with the utmost detail that I could venture to use 
in such a report, the circumstances of the somewhat famous Sulina- 
Danube improvement, to show how and under what circumstances a 
river-arm, discharging only one-third of the water that is discharged by 
the South Pass of the Mississippi River, has been made to afford a good 
navigable entrance, with an ‘‘effective depth” of twenty feet, while the 
bar “ advance,” instead of being accelerated, has been retarded. Those 
who examine the problem icithout the light of these results , would be slow 
to believe that the local circumstances were decidedly favorable; that 
they were more favorable than those offered by the Mississippi. The 
hardness of the shoals favors, indeed, construction, but indicates a more 
thorough sifting by the sea-waves of the sedimentary matter rolled 
along the bottom, while such a bar on a shallow coast directly exposed 
to storm-waves is usually an unpromising subject for improvement. 
The littoral current, at best feeble, scarcely, if at all, exceeds that which 
is imputed (“Iffiysics and Hydraulies of the Mississippi,” p. 449) to the 
Gulf waters of the Mississippi bars.* 

On the other hand, the very rapid deepening of the Gulf immediately 
off the bars, and the favorable exposure of their external slopes to the 
action of the sea-waves and currents generated by easterly storm-winds, 
are circumstances decidedly favorable. Surely there is ground here, 
especially when we weigh the inestimable benefit of an open river 
mouth, to pause at least long enough for a mature study and investi¬ 
gation, not merely on paper, but by surveys and measurement at the 
localities, to collect the special data which bear upon the application of 
the project to them, instead of, by a hasty pre-judgment founded on in¬ 
adequate knowledge, deciding that there is no remedy to the evils hut 
the gigantic and costly alternative of a ship-canal. 

It is proper, however, to allude to the more prominent objections. 
One of them is based upon the following, from “ Physies and Hydraulics 
of the Mississippi:” 

* Vessels making for the Southwest Pass from the capes of Florida are, after east 
and southeast gales, carried to the westward of their reckoning. Hence, in part, the 
construction of a costly light-house on Timbalier Island, sixty miles west of the South¬ 
west Pass. Major Damrell, light-house engineer, confirms the existence of a western 
current off Mobile Bay entrance. 







IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 123 


If the excavating power and depositing action of the Southwest Pass had been equal 
when the yearly advance of the bar was 700 feet instead of 338 feet, the least depth 
upon it would have been 21 feet. This increase of excavating power may be obtained 
by constructing two converging jettees, beginning where the depth of 22 feet is found, 
and extended to that depth outside the crest of the bar, which would give them a 
length of about 2.5 miles. * ■* * * * * * 

The depth of 21 feet thus obtained must be maintained by the annual extension of 
the jettees 700 feet into the Gulf. 

This dictum is founded upon a theory of bar formation, which is 
doubtless true, and yet does not contain the whole truth ; for were the 
Gulf waters fresh and of same specific gravity as those of the river, 
there would still be a bar; moreover, the stretching of any theory of so 
complicated phenomena to numerical results is generally putting upon it 
more than it will bear. Some confirmation may be attributed to the 
fact that Captain Howell’s surveys show an advance of 500 feet to the 
southwest bar, while under the operations of his dredge-boats; dredging 
by this method, or its equivalent, has been in operation during a con¬ 
siderable fraction of the high-water periods since 1853, and it would be 
desirable to know whether a decided acceleration of advance has result¬ 
ed ; at any rate we need a wider induction than Captain Howell’S sur¬ 
vey yet furnishes. Without pausing on this point, or discussing the 
applicability of the theory to an equal deepening by jettees, I prefer to 
dismiss the Southwest Pass, as one to which an experimental application 
of jettees would be unadvisable. So I have always regarded it. To 
obtain 25 feet depth of water, it would not be wise to enter into contest 
with the forces of motion developed in the discharge of a stream larger 
than the whole Danube. The excessive length of pier-construction 
simply to reach the bar to be deepened, should be decisive as to the 
matter of selection. 

The objection just treated, together with others arising from the pe¬ 
culiarities of Pass a Loutre, and the expense of construction, are dwelt 
upon at length in the report of the majority of this board, simply to show 
that the cost need not a priori be set down as out of reasonable bounds. 
I selected the Pass a Loutre, and, in a preliminary draught of a report 
made at New Orleans, sketched out an application of jettees. I stated 
that “ from the point in the pass where the depth of 25 feet ceases to 
obtain, to the outer crest of the bar, is about two and a half miles. This 
has reference to the pass below the division of the North Pass, not from 
any supposed lack of water, but because there was a shoal at the divis¬ 
ion ; and, in short, to make a full estimate for what others might allege 
to be necessary, I commenced above the North Pass, included the “ stop¬ 
ping” of that pass, and made jettees four miles long instead of two 
and a half. I placed my jettees in the natural banks or upon the shoals. 
The estimate of the majority is founded, apparently, upon taking a nor¬ 
mal distance apart of 2,200 feet, preserving perfect parallelism, (by which 
the jettees are throughout their entire length , over four and a half miles, 
laid in deep water.) The closing of the North Pass is pronounced not 
only a “necessary” but a “delicate” and withal costly operation, 
“ which must be sought at whatever cost in order to meet the desired 
improvement.” 

The exclusion rather than the addition of this water would be desira¬ 
ble,* but as this is not the place for discussion of projects, I simply 

* There is a very similar case presented at the St. George mouth of the Danube. The 
Kedrilles channel of the St. George branch, carrying two-thirds of the water, by a di¬ 
vision very similar to that at Pass a Loutre, reaches its bar at a distance ot two miles. 
In contemplating the improvement of this arm Sir Charles Hartley considered it would 
have been objectionable rather than desirable to close the other outlet. 




124 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


content myself with the bare statement, and remark farther that even 
if the water-way is to be restricted to 2,200 feet lor four and one-half 
miles, the selection of the best ground for the jettees at distances apart 
considerably greater than 2,200 feet is not debarred. Short auxiliary 
jettees of slight construction, perpendicular to the main ones, will con¬ 
tract the water-way. Such parallelism is not, however, suggested in 
the paragraph I have quoted from Physics and Hydraulics of the Mis¬ 
sissippi, nor practiced at the Sulina. 

For reasons above given the hypothetical application of the ma¬ 
jority of the board is erroneous in principle and elaborately unfavorable. 
An average section (fascines and ballast) of 32 square yards (say 12 
feet broad on top and 12 feet deep) is attributed the whole length of 
four and a half miles of each jettee, and on the bottom and slopes of this 
total of nine miles of u fascines and ballast*’ are laid an average of twenty 
tons of riprap per running yard, (increasing by 50 per cent, the average 
section just described,) a total of riprap (320,000 tons) more than one- 
third of that in the Delaware breakwater and ice-breaker. Two-thirds 
of the construction (admitting the lengths to be necessary) could be laid 
on the natural banks or on ground marked u bare at low water,” and be 
little more than levees, and generally the location would not be exposed 
to the violent sea-action which requires the voluminous re inforcement 
by riprap applied to sea-jettees of the character that seems to be 
adopted. (See Professional Papers, Corps of Engineers U. S. A., No. 22, 
pp. 60, 61.) The question submitted, however, is not so much u to recom¬ 
mend its trial 77 (of the jettee system) as to recommend its consideration , 
and that scrutiny and survey on which alone estimates can be based. 

For the same reason, however, that I have from the outset regarded 
the Southwest Pass as ineligible, I would as a subject of initial opera¬ 
tions dismiss from present consideration Pass a Loutre. In the discus¬ 
sion before the institution of civil engineers (Minutes 1861, 1862,) Sir 
Charles Hartley said u that he did not consider it an advantage to have a 
large body of water discharging at the entrance. That teas the only 
disadvantage of the fit. George as compared with the Sulina. The more 
the quantity of water the greater would be the amouut of deposit ; 77 
and it is a conclusion of that engineer that u it is more advisable 
to improve the mouth of a minor branch of a river rather than to 
grapple with the difficulties of a principal branch if that minor branch 
offer sufficient depth and width, or nearly so, for the navigation down 
to the point where its waters are discharged into the sea. 77 

If this language had been used to describe the South Pass of the Mis¬ 
sissippi, it could scarcely have been more exactly fitted. As the shortest 
it is the pass of which the natural advance is least rapid; it is nearly 
straight. Its average depth from the head of the passes to the head of 
its offshoot, Grand Bayou, is by Talcott 27 feet, by the most recent 
Coast Survey chart 38 feet, thence to inner edge of bar 24.J feet by Tal¬ 
cott, and 29 feet by Coast Survey, (1867.) Its least width is more than 
500 feet. We have here, then, a pass of which the natural capacity is 
almost precisely that which is needed, and of a magnitude amenable, 
with comparative ease, to works of improvement. Its channel can be 
easily improved and regulated, the bar at the head of the passes re¬ 
moved, minor outlets closed, and even (if desirable) more water be di¬ 
rected into it. From the bar the uearest unsubmerged shore is about 
two miles on the east side and one mile on the west, and these dis¬ 
tances would lie generally in very shoal water. Hence for an experi¬ 
mental trial this pass should be selected. 

The important fact that at the Sulina-Danube mouth the progress of 


IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 125 

bar-advance has been retarded rather than accelerated,* that in the 
opinion of the distinguished engineer who accomplished that work, such 
will generally be the effect of jettees (when the bar due to sediment of a 
muddy river is in question) should, I think, cause some hesitation in 
adopting a theoretical view of accelerated advance; especially as the 
theory leaves out of consideration the counteracting effects of currents 
and waves. But if reference is had to the theory, the case here offered is 
more analogous to that presented on page 415, Physics and Hydraulics 
of the Mississippi, in which the mouth is supposed removed to some 
point where the pass has its normal section and mean depth, and the 
Gulf to occupy its place, (i. e. that no bar has yet formed.) The carrying 
forward of the normal section and mean depth of a pass to the deep 
water of the Gulf has only this difference, that the process implies the 
erosion and deposit beyond of the material of the existing bar. In the 
hypothetical case the formation of the bar is admitted to require time. 

I am not called upon to make a plan nor an estimate. If successful 
at all, (and I have endeavored to show that success is promised,) the cost 
will be a small fraction of that of the canal. On the other hand, the 
advantages of an open river mouth are inestimable. The needs of a 
navigation so great as that which now exists, and which in the future 
of the great Mississippi Valley must be fifty-fold increased, demand it. 

It is said that u the time has come” when the needs of commerce de¬ 
mand the canal; but I answer that the time will come when there will 
be the same cry for a navigation unimpeded by locks— an open river 
mouth —which we now hear for a canal. But in whatever aspect the 
question be regarded, the use of the river mouth for the next ten years 
is simply inevitable. 

The conditions of the location and execution of a canal have received 
no adequate study. The plan, boldly and ably, yet so imperfectly, 
sketched out nearly forty years ago by one for seventeen years my com¬ 
manding officer or professional associate, W. H. Chase, is yet, in its en¬ 
gineering features, the best plan extant; and the grave objections to 
that apply with eveu greater force to the present project, and demand 
new studies of location and an entire revision of plans of execution. It 
would be a rash confidence which would contemplate a realized u Fort 
Saint Philip Ship-Canal” earlier than A. I). 1884. 

In the mean time shall the routes of commerce of the great West be 
yet more effectually than now diverted to the Atlantic ports; or shall the 
public confidence be directed to the present adequacy of the operations 
upon the bars; and shall the problem, which sooner or later must come , 
of an open river mouth, be solved? 

Respectfully submitted. 

J. G. BARNARD, 

Col. of Engineers and Bet. Maj. Gen., President of Board. 

Brig. Gen. A. A.‘ Humphreys, 

Chief of Engineers, United States Army , 

Washington , I). C. 


* The permanent deepening on the bar which existed at this Danube mouth appears 
to be a well-established fact. It is an experimental demonstration of the efficacy of 
longitudinal jettees for improving the bars at the sea-mouths of rivers. (Annales des 
Ponts et Chaussdes, November, 1S7*2.) 








126 IMPROVEMENT OF MOUTH OF THE MISSISSIPPI RIVER. 


6 . 


Engineer Office, United States Army, 

Newport , R. J., January 15, 1874. 

General: As a member of the board of engineers considering the 
Fort Saint Philip canal project for connecting the deep waters of the Mis¬ 
sissippi River and the Gulf of Mexico, directed by you to also consider 
the alternative proposition of making this connection by deepening 
the water over the bars in the natural outlets, I beg leave to say that 
on this last proposition I do not feel possessed of the data for a de¬ 
tailed report, nor do I see how these can be obtained but by costly expe¬ 
rience. Any conclusions reached now must unavoidably rest upon what 
is, in a measure, assumed, and opposite conclusions will be reached by 
others using the same liberty. 

My mind, however, is fixed upon the idea that the canal is the only 
project that will meet the commercial, naval, and military demands of 
the United States. Its feasibility has never been doubted by any one, 
and only on account of its cost have other methods been heretofore rec¬ 
ommended. These other methods have always been regarded as experi¬ 
ments, and the reliance has been that, if they failed, the canal, as a 
final resort, was certain. 

I believe the time has come when that which appears certain should 
be tried first. 

The cost of the canal will not be great compared with the end to be 
gained; and there is no certainty that we will not have to come to it 
after great delay and expenditure upon other methods, none of which, 
when abandoned, will have aided in the least toward constructing the 
canal. 


Very respectfully, 

G. K. WARREN, 

Maj. of Engineers, Bvt. Mag. Gen. United States Army. 
Brig. Gen. A. A. Humphreys, 

Chief of Engineers , United States Army. 


O 


LIST of MAPS accompanying Reports upon Improvement of the 

mouths of the Mississippi. 

[ Ho. Ex. Doc. 220, 43c? Con(/.. l.s? Sess. ] 


1. Geologie pratique dela Louisiane par R. Thomassy. Entree 
du Mississipi en 1722, 1724, & 1731. [Map showing tlie 
changes which took place at the Balize during the above years.] 

2. Map showing the supposed limits of the area in which the 
center line of the proposed canal would he located according to 
Major Warren’s idea. 


o 

O. 


Delta of the Mississippi River from Captain Talcott’s sur¬ 
vey in 1838, with comparative profiles of South-West and South 
Passes. 


4. Comparative Profiles of the South-West Pass, and South 
Pass, Delta of the Mississippi River and of the Sulina branch of 
the Danube. 


5. Sulina Mouth of the Danube from the “Minutes of proceed¬ 
ings, Institution of Civil Engineers, London Yol. XXI, Session 
1861-62.” 

6. Comparative Chart of the Surveys of 1838, 1867 and 
1874. of the South-West and South Passes, Mississippi River, 
Louisiana. 




























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BE LAlOTJTwSIANE MR R.THOMASSY: 


PRATIQUE 


.ARCHIVES SC'IKNTIFIQUES DE .LAMARINE 


(a = monticules de bauc.) 


dr. derive. 




; ^aw a 








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■ ■ ■•• •'•'•■••.••■.•••■• ■ 










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DIJMISSISSIPI 




DU MSSISSIPI 


DIJMISSISSIPI 


pn 1724. 

AVEC LE PORT DE JiA HAJjISE 
etla passe ordinate 
de Aoubleeparle couraat 


en 1722 

avec projet de fort 

et de place maritime 


an 20 AvT'il 1731, 
progres des alien ssemeiUs 
survenus clepuis 1724. 


avec 


KcheJIe de OooToises. 


KehoJle 


de 60 0 Tois os 


KcheDe de 600 Toises 


l Carte levee par Re la. Tour) 
ingenieur de let C& des Jndes. 


(its Chiifres marqutnt Tes pied-i dean d bassc maree) 


/ Carte- anonyms des mernes archives.) 


es Chiffres martfuent Itspieds dean a hassc maree 


(Carte levdeptu‘ De Pnuger) 


s inarqwent Its pieds dean d basst maree, 


ineienieur du.Roi. 


ui. 


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1&S 

Office of<*^ 

DELTA 

of the 

MISSISSIPPI HIVEII, 

from Capt. TaleoIt’s Survey 


made in 18 .‘> 8 . 

Seal e 

a miles 

figures denote soundings in feet. 


/, ROBINSON'S 

6 i. THpoiBK. ''a*".? 

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Horizontal Scale of Profiles, 1.100,000. 

q_10000_20000 


Yeidicai Scale, 1: 1200. 


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Vertical Scale distorted 83 Bs times- 


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Profile of the South West Pass 

Jrom the Survey*?oCCopt. (■ Dorvedf, irv < /a 71 % if Dec? K>fi <&- fel • / <f March . 

1874 . 

Sec cuxornparcyingcorriparative, ProfdxTS, on aZargcrscaZe 




6 MUes. 






3000 0* Poet 


300 Feet. 



Survey of /838. 


Profile of the South Pass 

from tJi/- 'Surveys- of (opt. Howell,, March, 13 S* to April It f 1 


1874 . 


'See (tcronpastg tup comp uni t>i 'c Profiles, or. a larger scalo 






















































































































































































































































































































































































































































































































































































































































































































Eueravetl in the Office of the Grief of Engineers. 










































































































































































































































































































































Engraved in llmdiHee oflhe Chief of Engineers. 


V OM PARATIVE C HART 

of the 

SimVEVS OF lU3a, 1067, fc 1.874, OF 

SOUTH WEST & SOUTH PASSES 

Mississippi Delta, La. 

propuiuul in 

1874. 

. V ofe . Soandtnqs arc expressed in feet. 


'2A U5 12 6 


South West Pass 

■Mississippi Della. 

/tedtzetid fi-om {'apt TctZttol/.s Surrauof 

1838 . 


’East Hayo 


27« 




■Iwt 27p 


South West Pass 
M ississippi J )<‘lUi. 

deduced from Cap! Howells Survey, vix 

from Pilot Town to Staler Island, in January 1873, 
Stake Island., Sea ward, in December 1873, •& 
February d-March 187b. 





Scott's Bay on 


*il«>l Town 


26 15 


Stn/.nc 

f.sftt/ttr 


/ 7 


f 30 / 

t f 
1 * 2 / / 


S. 


36' |2 ' 

24 n \ 


14 




81 


96 


78 


87 

ftp 


w iot 

15 

>" 04 ,8 ' 

24 

.. 48 °sv., Cat, 21 o0 

w> /tuoij V-*° 

. y' ~) 55 54 3C 

/ • 57 « 39 


73 


128 • H4 114 


66 . 

69 


54 


54 




99 90 


126 


84 


114 W8 


I DR 


120 


140 

150 


127 


123 

132 


84 ^ 

,99 U'| 

'•v.. 98 

103 


100 ' 


153 

160' 


180' 

186 


24 


36 


Scale of Feet. 


South Pass 

Mi s sis sippi X) el 1 a 

Reduced from (ci/)f 'faicoits •Surreu of 

1838 . 



18 


14.0 


165 


J44 


18 

124 

36 

54 


no 4.i 


-■south 
, nutin- 

.-) o yks 


9.7 


12 

18 


17 

24. 


-.10.1 


36 5U 

54 


/ih Point 


South Pass 


JV1 i ,s s i s s ip p i D el t a 

Reduced icom the TJ. *S‘. C. ’Sari r ey 
.Manuscript cKap of 

1867 . 



*1 

” • A 


6 test curce 

a .. r 

IS „ „ 


21 V 7 ; 4- "Sj eV ■' 
l * V- 7 Sc»i4l 

* 4> « 40 

3.5 w l» 

, RreaJcera H • - -f '—i 

f 5 -r^ : 38 

5 \ d / ' 3 ST " 36 


6' / /.0 16" 
12*'/ v - vr 

18' 31 
27 

30 




Light Ho 


South Pass 

Mississippi Delta 

ft ee/need'fro tit 7 apt f/o traits Surratt o/ 

1874. 



fi 

^ I 

^ S* 

frl 


.32 


27. 


6 . 10 


S i. . io 

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Si fi 

-./fA 

VJ \ 


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38 


69. 


45 


fid re at 
Low Title 


10 8 


20 ' 
4o' 


60 

60 




23 36 56 


27 


57 


84 


17 

34 

45 


23 


57 


28 


78 


48 


84 


84 


80' 


84 


2 > 2 \ 


\i»m 
20 o' 


0 1 2 3 4 5 6 7 8 9 JO TJ 12 13 H 15 16 17 la ID ‘20 21 

Seale of Statute Miles. 


*-’3 3-1 23 26 27 2« 20 00 31 32 33 34 35000 Feet 


“Milos 


220 ' 


174 


90 


198 


96 

IOO* 


120 


246 


156 

168 


204 


160 
180' 


200 


264 


246 


244 


318 


270 


24o' 


I! 




2 94 

300 1 806 

312 


306 



342 


340' (i/rvr. 


306 


*354 


































































































































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